Constellation Acquisition Corp I

DEF 14A 1 ea0271395-02.htm PROXY STATEMENT

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

Check the appropriate box:

Constellation Acquisition Corp I

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

LETTER TO SHAREHOLDERS OF CONSTELLATION ACQUISITION CORP I

1290 Avenue of the Americas, 10 th Floor

New York, NY 10104

Dear Constellation Acquisition Corp I Shareholder:

You are cordially invited to attend an extraordinary general meeting of Constellation Acquisition Corp I, a Cayman Islands exempted company (“Constellation” or the “Company”), which will be held on January 27, 2026, at 11:00 a.m., Eastern Time, at the offices of Kirkland & Ellis LLP located at 601 Lexington Avenue, New York, NY 10022, and via a virtual meeting, or at such other time, on such other date and at such other place to which the meeting may be postponed or adjourned (the “Shareholder Meeting”).

The Shareholder Meeting will be conducted via live webcast, but the physical location of the Shareholder Meeting will remain at the location specified above for the purposes of our amended and restated memorandum and articles of association (the “Memorandum and Articles of Association”). If you wish to attend the Shareholder Meeting in person, you must reserve your attendance at least two business days in advance of the Shareholder Meeting by contacting Constellation’s Chief Executive Officer at ir@constellationacquisition.com by 11:00 a.m., Eastern Time, on January 23, 2026 (two business days prior to the initially scheduled meeting date). You will be able to attend the Shareholder Meeting online, vote and submit your questions during the Shareholder Meeting by visiting https://www.cstproxy.com/constellationacquisition/2026. The attached notice of the Shareholder Meeting and proxy statement describe the business Constellation will conduct at the Shareholder Meeting and provide information about Constellation that you should consider when you vote your shares. As more fully described in the attached proxy statement, which is dated January 15, 2026, and is first being mailed to shareholders on or about that date, the Shareholder Meeting will be held for the purpose of considering and voting on the following proposals:

1. Proposal No. 1 — Extension Amendment Proposal— To amend, by way of special resolution, Constellation’s Memorandum and Articles of Association to extend the date (the “Termination Date”) by which Constellation has to consummate a Business Combination (as defined below) (the “Articles Extension”) from January 29, 2026 (the “Original Termination Date”) to February 28, 2026 (the “Articles Extension Date”) and to allow Constellation, without another shareholder vote, to elect to extend the Termination Date to consummate a Business Combination on a monthly basis for up to eleven times by an additional one month each time after the Articles Extension Date, by resolution of Constellation’s board of directors (the “Board”), if requested by Constellation Sponsor LP, a Delaware limited partnership (the “Sponsor”), and upon five days’ advance notice prior to the applicable Termination Date (each, an “Additional Articles Extension Date”) for an aggregate extension period of up to twelve months after the Original Termination Date, ending no later than January 29, 2027, unless the closing of a Business Combination shall have occurred prior thereto (the “Extension Amendment Proposal”); and

2. Proposal No. 2 — Adjournment Proposal —To adjourn, by way of ordinary resolution, the Shareholder Meeting to a later date or dates or indefinitely, if necessary, (i) to permit further solicitation and vote of proxies if, based upon the tabulated vote at the time of the Shareholder Meeting, there are insufficient Class A ordinary shares, par value of US$0.0001 per share, of the Company (the “Class A Ordinary Shares”), and Company’s Class B ordinary shares, par value of US$0.0001 per share, of the Company (the “Class B Ordinary Shares” and together with Class A Ordinary Shares, the “Ordinary Shares”) in the capital of Constellation represented (either in person or by proxy) to approve the Extension Amendment Proposal or (ii) where the Board has determined it is otherwise necessary (the “Adjournment Proposal”).

If the Extension Amendment Proposal is approved and the Articles Extension becomes effective, within ten business days of the date of the Shareholder Meeting, the Sponsor (or one or more of its affiliates, members or third-party designees) (the “Lender”) shall make a deposit into the Company’s trust account (the “Trust Account”) of $5,000, in exchange for a non-interest bearing, unsecured promissory note issued by Constellation to the Lender. In addition, if the Extension Amendment Proposal is approved and the Articles Extension becomes effective, in the event that Constellation has not consummated an initial Business Combination by February 28, 2026, without approval of Constellation’s public shareholders, Constellation may, by resolution of the Board, if requested by the Sponsor, and upon five days’ advance notice prior to the applicable Termination Date, extend the Termination

Date up to eleven times, each by one additional month (for a total of up to eleven additional months to complete a Business Combination), provided that the Lender will deposit $5,000 into the Trust Account for each such monthly extension, for an aggregate deposit of up to $55,000 (if all eleven additional monthly extensions are exercised), in exchange for a non-interest bearing, unsecured promissory note issued by Constellation to the Lender. If Constellation completes a Business Combination, it will, at the option of the Lender, repay the amounts loaned under the promissory note. If Constellation does not complete a Business Combination by the applicable Termination Date, such promissory note will be repaid only from funds held outside of the Trust Account or will be forfeited, eliminated or otherwise forgiven.

The purpose of the Extension Amendment Proposal and, if necessary, the Adjournment Proposal, is to allow Constellation additional time to complete a Business Combination. You are not being asked to vote on a Business Combination at this time.

The Memorandum and Articles of Association provide that Constellation has until January 29, 2026 to complete its initial Business Combination. Constellation’s Board has determined that it is in the best interests of Constellation to seek an extension of the Termination Date and have Constellation’s shareholders approve the Extension Amendment Proposal to allow for a period of additional time to consummate a Business Combination. Without the Articles Extension, Constellation believes that Constellation will not be able to complete a Business Combination on or before the Termination Date. If that were to occur, Constellation would be precluded from completing a Business Combination and would be forced to liquidate.

Constellation reserves the right at any time to postpone or cancel the Shareholder Meeting (by means of adjourning the Shareholder Meeting indefinitely) and not to submit to its shareholders the Extension Amendment Proposal or implement the Articles Extension. In the event the Shareholder Meeting is postponed, adjourned or canceled, and Constellation is unable to complete a Business Combination on or before the Termination Date, Constellation will dissolve and liquidate in accordance with the Memorandum and Articles of Association.

As contemplated by the Memorandum and Articles of Association, the holders of Constellation’s Class A Ordinary Shares issued as part of the Units (as defined below) sold in Constellation’s initial public offering (the “Public Shares”) may elect to redeem all or a portion of their Public Shares in exchange for their pro rata portion of the funds held in a trust account (the “Trust Account”) established to hold a portion of the proceeds of the initial public offering and the concurrent sale of the private placement warrants, if the Articles Extension is implemented, regardless of how such public shareholders vote in regard to the Extension Amendment Proposal. If the Extension Amendment Proposal is approved by the requisite vote of shareholders, the holders of Public Shares remaining after the redemption will retain their right to redeem their Public Shares in connection with a Business Combination or liquidation, subject to any limitations set forth in the Memorandum and Articles of Association.

On January 12, 2026, the most recent practicable date prior to the date of the accompanying proxy statement, the redemption price per share was approximately $13.37, based on the aggregate amount on deposit in the Trust Account of approximately $860,165 as of January 12, 2026 (including interest not previously released to Constellation to pay its taxes), divided by the total number of then outstanding Public Shares. The redemption price per share will be calculated based on the aggregate amount on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to Constellation to pay its taxes, if any, two business days prior to the initially scheduled date of the Shareholder Meeting. The closing price of the Class A Ordinary Shares on OTCID Basic Market (“OTCID”) on January 14, 2026 was $12.99. Accordingly, if the market price of the Class A Ordinary Shares were to remain the same until the date of the Shareholder Meeting, exercising redemption rights would result in a public shareholder receiving approximately $0.38 more per share than if the shares were sold in the open market (based on the per share redemption price as of January 12, 2026). Constellation cannot assure shareholders that they will be able to sell their Class A Ordinary Shares in the open market, even if the market price per share is lower than the redemption price stated above, as there may not be sufficient liquidity in its Securities (as defined below) when such shareholders wish to sell their shares. Constellation believes that such redemption right enables its public shareholders to determine whether to sustain their investments for an additional period if Constellation does not complete a Business Combination on or before the Termination Date.

If the Extension Amendment Proposal is not approved, and a Business Combination is not completed on or before the Termination Date, Constellation will: (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public

Shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to Constellation (less taxes payable and up to $100,000 of interest to pay dissolution expenses), divided by the total number of the then-outstanding Public Shares, which redemption will completely extinguish public shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of Constellation’s remaining shareholders and the Board, liquidate and dissolve, subject in each case to Constellation’s obligations under Cayman Islands law to provide for claims of creditors and other requirements of applicable law. There will be no distribution from the Trust Account with respect to Constellation’s Warrants (as defined below), which will expire worthless in the event Constellation dissolves and liquidates the Trust Account.

Subject to the foregoing, the approval of the Extension Amendment Proposal requires a special resolution under Cayman Islands law, being the affirmative vote of at least a two-thirds (2/3) majority of the votes cast by the holders of Class A Ordinary Shares and Class B Ordinary Shares voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the Shareholder Meeting.

On January 16, 2024, Constellation voluntarily delisted its Class A Ordinary Shares, redeemable warrants, each one whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 (the “Warrants”), and units, each consisting of one Class A Ordinary Share and one-third of one redeemable warrant (the “Units” and together with the Ordinary Shares and the Warrants, the “Securities”), from the New York Stock Exchange and began trading its Securities on the over-the-counter market. The Class A Ordinary Shares are currently quoted on the OTCID under the trading symbol “CSTAF,” the Warrants are currently quoted on OTCID under the trading symbol “CSTWF”, and the Units are currently quoted on the OTCID under the trading symbol “CSTUF.”

Constellation remains subject to the periodic reporting requirements of the U.S. Securities Exchange Act of 1934, as amended.

Approval of the Adjournment Proposal requires an ordinary resolution under Cayman Islands law, being the affirmative vote of at least a majority of the votes cast by the holders of the issued Ordinary Shares, voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the Shareholder Meeting. The Adjournment Proposal will only be put forth for a vote if there are not sufficient votes to approve the Extension Amendment Proposal at the Shareholder Meeting or if the Board has determined it is otherwise necessary.

The Board has fixed the close of business on December 30, 2025 as the date for determining Constellation’s shareholders entitled to receive notice of and vote at the Shareholder Meeting and any adjournment thereof. Only holders of record of Ordinary Shares on that date are entitled to have their votes counted at the Shareholder Meeting or any adjournment thereof.

The Board of Constellation believes that it is in the best interests of Constellation that Constellation obtain the Articles Extension. After careful consideration of all relevant factors, the Board has determined that the Extension Amendment Proposal and the Adjournment Proposal are in the best interests of Constellation and its shareholders and has declared it advisable and recommends that you vote or give instruction to vote “FOR” the Extension Amendment Proposal and “FOR” the Adjournment Proposal.

Your vote is very important. Whether or not you plan to attend the Shareholder Meeting, please vote as soon as possible by following the instructions in the accompanying proxy statement to make sure that your shares are represented and voted at the Shareholder Meeting. If you hold your shares in “street name” through a bank, broker or other nominee, you will need to follow the instructions provided to you by your bank, broker or other nominee to ensure that your shares are represented and voted at the Shareholder Meeting. The approval of the Extension Amendment Proposal requires a special resolution under Cayman Islands law, being the affirmative vote of at least atwo-thirds (2/3) majority of the votes cast by the holders of the issued Ordinary Shares, voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the Shareholder Meeting. Approval of the Adjournment Proposal requires an ordinary resolution under Cayman Islands law, being the affirmative vote of at least a majority of the votes cast by the holders of the issued Ordinary Shares, voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the

Shareholder Meeting. Accordingly, if you fail to vote in person or by proxy at the Shareholder Meeting, your shares will not be counted for the purposes of determining whether the Extension Amendment Proposal and the Adjournment Proposal are approved by the requisite majorities.

If you sign, date and return your proxy card without indicating how you wish to vote, your proxy will be voted “FOR” each of the proposals presented at the Shareholder Meeting. If you fail to return your proxy card or fail to instruct your bank, broker or other nominee how to vote, and do not attend the Shareholder Meeting in person, the effect will be that your shares will not be counted for purposes of determining whether a quorum is present at the Shareholder Meeting and will not have any effect on whether the proposals are approved. If you are a shareholder of record and you attend the Shareholder Meeting and wish to vote in person, you may withdraw your proxy and vote in person.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR CLASS A ORDINARY SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO CONSTELLATION’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE INITIALLY SCHEDULED DATE OF THE SHAREHOLDER MEETING. IN ORDER TO EXERCISE YOUR REDEMPTION RIGHT, YOU NEED TO IDENTIFY YOURSELF AS A BENEFICIAL HOLDER AND PROVIDE YOUR LEGAL NAME, PHONE NUMBER AND ADDRESS IN YOUR WRITTEN DEMAND. YOU MAY TENDER YOUR SHARES BY EITHER TENDERING OR DELIVERING YOUR SHARES (AND CERTIFICATES (IF ANY) AND OTHER REDEMPTION FORMS TO THE TRANSFER AGENT OR BY TENDERING OR DELIVERING YOUR SHARES (AND SHARE CERTIFICATES (IF ANY) AND OTHER REDEMPTION FORMS) ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

Enclosed is the proxy statement containing detailed information about the Shareholder Meeting, the Extension Amendment Proposal and the Adjournment Proposal. Whether or not you plan to attend the Shareholder Meeting, Constellation urges you to read this material carefully and vote your shares.

By Order of the Board of Directors of Constellation Acquisition Corp I

/s/ Chandra R. Patel

Chandra R. Patel

Chairman of the Board of Directors

CONSTELLATION ACQUISITION CORP I

1290 Avenue of the Americas, 10 th Floor

New York, NY 10104

NOTICE OF AN EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS

OF CONSTELLATION ACQUISITION CORP I

TO BE HELD ON JANUARY 27, 2026

To the Shareholders of Constellation Acquisition Corp I:

NOTICE IS HEREBY GIVEN that an extraordinary general meeting of Constellation Acquisition Corp I, a Cayman Islands exempted company (“Constellation” or the “Company”), will be held on January 27, 2026, at 11:00 a.m., Eastern Time (the “Shareholder Meeting”), at the offices of Kirkland & Ellis LLP located at 601 Lexington Avenue, New York, NY 10022, and via a virtual meeting, or at such other time, on such other date and at such other place to which the meeting may be postponed or adjourned.

The Shareholder Meeting will be conducted via live webcast, but the physical location of the Shareholder Meeting will remain at the location specified above for the purposes of our amended and restated memorandum and articles of association (the “Memorandum and Articles of Association”). If you wish to attend the Shareholder Meeting in person, you must reserve your attendance at least two business days in advance of the Shareholder Meeting by contacting Constellation’s Chief Executive Officer at ir@constellationacquisition.com by 11:00 a.m., Eastern Time, on January 23, 2026 (two business days prior to the initially scheduled meeting date). You will be able to attend the Shareholder Meeting online, vote and submit your questions during the Shareholder Meeting by visiting https://www.cstproxy.com/constellationacquisition/2026.

You are cordially invited to attend the Shareholder Meeting that will be held for the purpose of considering and voting on (i) an extension amendment proposal to amend, by way of special resolution, the Memorandum and Articles of Association to extend the date (the “Termination Date”) by which Constellation has to consummate a Business Combination (the “Articles Extension”) from January 29, 2026 (the “Original Termination Date”) to February 28, 2026 (the “Articles Extension Date”) and to allow Constellation, without another shareholder vote, to elect to extend the Termination Date to consummate an initial business combination (a “Business Combination”) on a monthly basis for up to eleven times by an additional one month each time after the Articles Extension Date, by resolution of Constellation’s board of directors (the “Board”), if requested by Constellation Sponsor LP, a Delaware limited partnership (the “Sponsor”), and upon five days’ advance notice prior to the applicable Termination Date (each, an “Additional Articles Extension Date”) for an aggregate extension period of up to twelve months after the Original Termination Date, ending no later than January 29, 2027, unless the closing of a Business Combination shall have occurred prior thereto (the “Extension Amendment Proposal”), and (ii) an adjournment proposal to adjourn, by way of ordinary resolution, the Shareholder Meeting to a later date or dates or indefinitely, if necessary, (a) to permit further solicitation and vote of proxies if, based upon the tabulated vote at the time of the Shareholder Meeting, there are insufficient Class A ordinary shares, par value of US$0.0001 per share, of the Company (the “Class A Ordinary Shares”) and Class B ordinary shares, par value of US$0.0001 per share, of the Company (the “Class B Ordinary Shares” and together with Class A Ordinary Shares, the “Ordinary Shares”) represented (either in person or by proxy) at the Shareholder Meeting to approve the Extension Amendment Proposal or (b) where the Board has determined it otherwise necessary (the “Adjournment Proposal”), each as more fully described below in the accompanying proxy statement, which is dated January 15, 2026, and is first being mailed to shareholders on or about that date. The full text of the proposals to be voted upon at the Shareholder Meeting is as follows:

1. Proposal No. 1— The Extension Amendment Proposal—RESOLVED, as a special resolution that:

“In the event that the Company does not consummate a Business Combination upon the date which is the later of (i) February 28, 2026 (or such later date up to, and including, January 29, 2027, if applicable under the provisions of this Article 49.7) and (ii) such later date as may be approved by the Members in accordance with the Articles (in any case, such date being referred to as the “Termination Date”), the Company shall (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter,

redeem the Public Shares, at a per-Share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to Constellation (less taxes payable and up to US$100,000 of interest to pay liquidation expenses), divided by the number of the then-outstanding Public Shares, which redemption will completely extinguish public Members’ rights as Members (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of Constellation’s remaining shareholders and the Board, liquidate and dissolve, subject in each case to Constellation’s obligations under Cayman Islands law to provide for claims of creditors and other requirements of Applicable Law.

Notwithstanding the foregoing or any other provisions of the Articles, in the event that the Company has not consummated a Business Combination by February 28, 2026, the Company may, without another shareholder vote, elect to extend the date to consummate a Business Combination on a monthly basis for up to eleven times by an additional one month each time after February 28, 2026, by resolution of the Directors, if requested by the Sponsor in writing, and upon five days’ advance notice prior to the applicable Termination Date, until January 29, 2027, provided that the Sponsor (or one or more of its affiliates, members or third-party designees) (the “Lender”) will deposit US$5,000 into the Trust Account for each such monthly extension, for an aggregate deposit of up to US$55,000 (if all eleven additional monthly extensions are exercised), in exchange for a non-interest bearing, unsecured promissory note issued by the Company to the Lender. If the Company completes a Business Combination, it will, at the option of the Lender, repay the amounts loaned under the promissory note. If the Company does not complete a Business Combination by the applicable Termination Date, such promissory note will be repaid only from funds held outside of the Trust Account or will be forfeited, eliminated or otherwise forgiven.”

b) Article 49.8(a) of Constellation’s Memorandum and Articles of Association be deleted in its entirety and replaced with the following new Article 49.8(a): “to modify the substance or timing of the Company’s obligation to allow redemption in connection with a Business Combination or to redeem 100 per cent of the Public Shares if the Company does not consummate a Business Combination prior to February 28, 2026 (or up to January 29, 2027, if applicable under the provisions of Article 49.7);”

2. Proposal No. 2 — The Adjournment Proposal —RESOLVED, as an ordinary resolution, that the adjournment of the Shareholder Meeting to a later date or dates or indefinitely if necessary, (i) to permit further solicitation and vote of proxies if, based upon the tabulated vote at the time of the Shareholder Meeting, there are insufficient Class A Ordinary Shares and Class B Ordinary Shares in the capital of Constellation represented (either in person or by proxy) at the Shareholder Meeting to approve the Extension Amendment Proposal or (ii) where the Board of Constellation has determined it is otherwise necessary.

Each of the Extension Amendment Proposal and the Adjournment Proposal is more fully described in the accompanying proxy statement. Please take the time to read carefully each of the proposals in the accompanying proxy statement before you vote.

Constellation reserves the right at any time to postpone or cancel the Shareholder Meeting (by means of adjourning the Shareholder Meeting indefinitely) and not to submit to its shareholders the Extension Amendment Proposal or implement the Articles Extension. In the event the Shareholder Meeting is postponed, adjourned or canceled, and Constellation is unable to complete a Business Combination on or before the Termination Date, Constellation will dissolve and liquidate in accordance with the Memorandum and Articles of Association.

If the Extension Amendment Proposal is approved and the Articles Extension becomes effective, within ten business days of the date of the Shareholder Meeting, the Lender shall make a deposit into the Company’s trust account (the “Trust Account”) established to hold a portion of the proceeds of the initial public offering (the “Initial Public Offering”) of $5,000, in exchange for a non-interest bearing, unsecured promissory note issued by Constellation to the Lender. In addition, if the Extension Amendment Proposal is approved and the Articles Extension becomes effective, in the event that Constellation has not consummated a Business Combination by February 28, 2026, without approval of Constellation’s public shareholders, Constellation may, by resolution of the Board, if requested by the Sponsor, and upon five days’ advance notice prior to the applicable Termination

Date, extend the Termination Date up to eleven times, each by one additional month (for a total of up to eleven additional months to complete a Business Combination), provided that the Lender will deposit $5,000 into the Trust Account for each such monthly extension, for an aggregate deposit of up to $55,000 (if all eleven additional monthly extensions are exercised), in exchange for a non-interest bearing, unsecured promissory note issued by Constellation to the Lender. If Constellation completes a Business Combination, it will, at the option of the Lender, repay the amounts loaned under the promissory note. If Constellation does not complete a Business Combination by the applicable Termination Date, such promissory note will be repaid only from funds held outside of the Trust Account or will be forfeited, eliminated or otherwise forgiven.

The purpose of the Extension Amendment Proposal and, if necessary, the Adjournment Proposal, is to allow Constellation additional time to complete a Business Combination. You are not being asked to vote on a Business Combination at this time.

The Memorandum and Articles of Association provide that Constellation has until January 29, 2026 to complete its initial Business Combination. The Board has determined that it is in the best interests of Constellation to seek an extension of the Termination Date and have Constellation’s shareholders approve the Extension Amendment Proposal to allow for a period of additional time to consummate a Business Combination. Without the Articles Extension, Constellation believes that Constellation will not be able to complete a Business Combination on or before the Termination Date. If that were to occur, Constellation would be precluded from completing a Business Combination and would be forced to liquidate.

The Board of Constellation believes that it is in the best interests of Constellation that Constellation obtain the Articles Extension. After careful consideration of all relevant factors, the Board has determined that the Extension Amendment Proposal and the Adjournment Proposal are in the best interests of Constellation and its shareholders and has declared it advisable and recommends that you vote or give instruction to vote “FOR” the Extension Amendment Proposal and “FOR” the Adjournment Proposal.

As contemplated by the Memorandum and Articles of Association, the holders of Constellation’s Class A Ordinary Shares issued as part of the Units (as defined below) sold in Constellation’s initial public offering (the “Public Shares”) may elect to redeem all or a portion of their Public Shares in exchange for their pro rata portion of the funds held in the Trust Account and the concurrent sale of the private placement warrants (the “Private Placement Warrants”), if the Articles Extension is implemented, regardless of how such public shareholders vote in regard to the Extension Amendment Proposal. If the Extension Amendment Proposal is approved by the requisite vote of shareholders, the holders of Public Shares remaining after the redemption will retain their right to redeem their Public Shares in connection with a Business Combination or liquidation, subject to any limitations set forth in the Memorandum and Articles of Association, as amended.

On January 12, 2026, the most recent practicable date prior to the date of this proxy statement, the redemption price per share was approximately $13.37, based on the aggregate amount on deposit in the Trust Account of approximately $860,165 as of January 12, 2026 (including interest not previously released to Constellation to pay its taxes, if any), divided by the total number of then outstanding Public Shares. The redemption price per share will be calculated based on the aggregate amount on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to Constellation to pay its taxes, if any, two business days prior to the initially scheduled date of the Shareholder Meeting. The closing price of the Class A Ordinary Shares on the OTCID Basic Market (“OTCID”) on January 14, 2026 was $12.99. Accordingly, if the market price of the Class A Ordinary Shares were to remain the same until the date of the Shareholder Meeting, exercising redemption rights would result in a public shareholder receiving approximately $0.38 more per share than if the shares were sold in the open market (based on the per share redemption price as of January 12, 2026). Constellation cannot assure shareholders that they will be able to sell their Class A Ordinary Shares in the open market, even if the market price per share is lower than the redemption price stated above, as there may not be sufficient liquidity in its Securities (as defined below) when such shareholders wish to sell their shares. Constellation believes that such redemption right enables its public shareholders to determine whether to sustain their investments for an additional period if Constellation does not complete a Business Combination on or before the Termination Date.

Approval of the Extension Amendment Proposal is a condition to the implementation of the Articles Extension.

Constellation cannot predict the amount that will remain in the Trust Account following the redemption if the Extension Amendment Proposal is approved, and the amount remaining in the Trust Account may be only a small fraction of the approximately $860,165 that was in the Trust Account as of January 12, 2026 (including interest not previously released to Constellation to pay its taxes).

If the Extension Amendment Proposal is not approved, and a Business Combination is not completed on or before the Termination Date, Constellation will: (i) cease all operations except for the purpose of winding up; (ii) as promptly as reasonably possible but not more than ten business days thereafter, redeem the Public Shares, at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to Constellation (less taxes payable and up to $100,000 of interest to pay liquidation expenses), divided by the number of the then-outstanding Public Shares, which redemption will completely extinguish public shareholders’ rights as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible following such redemption, subject to the approval of Constellation’s remaining shareholders and the Board, liquidate and dissolve, subject in each case to Constellation’s obligations under Cayman Islands law to provide for claims of creditors and other requirements of applicable law. There will be no distribution from the Trust Account with respect to Constellation’s Warrants (as defined below), which will expire worthless in the event Constellation dissolves and liquidates the Trust Account.

In the event of a liquidation, the Sponsor and certain initial shareholders of Constellation (the “Initial Shareholders”) will not receive any monies held in the Trust Account as a result of their ownership of 7,750,000 Ordinary Shares held by the Initial Shareholders, and 5,466,667 Private Placement Warrants, which were purchased by the Sponsor in a private placement which occurred simultaneously with the completion of the Initial Public Offering and concurrently with the underwriters’ partial exercise of their over-allotment option. As a consequence, a liquidating distribution will be made only with respect to the Public Shares.

TO EXERCISE YOUR REDEMPTION RIGHTS, YOU MUST DEMAND IN WRITING THAT YOUR CLASS A ORDINARY SHARES ARE REDEEMED FOR A PRO RATA PORTION OF THE FUNDS HELD IN THE TRUST ACCOUNT AND TENDER YOUR SHARES TO CONSTELLATION’S TRANSFER AGENT AT LEAST TWO BUSINESS DAYS PRIOR TO THE INITIALLY SCHEDULED DATE OF THE SHAREHOLDER MEETING. IN ORDER TO EXERCISE YOUR REDEMPTION RIGHT, YOU NEED TO IDENTIFY YOURSELF AS A BENEFICIAL HOLDER AND PROVIDE YOUR LEGAL NAME, PHONE NUMBER AND ADDRESS IN YOUR WRITTEN DEMAND. YOU MAY TENDER YOUR SHARES BY EITHER TENDERING OR DELIVERING YOUR SHARES (AND SHARE CERTIFICATES (IF ANY) AND OTHER REDEMPTION FORMS) TO THE TRANSFER AGENT OR BY TENDERING OR DELIVERING YOUR SHARES (AND SHARE CERTIFICATES (IF ANY) AND OTHER REDEMPTION FORMS) ELECTRONICALLY USING THE DEPOSITORY TRUST COMPANY’S DWAC (DEPOSIT WITHDRAWAL AT CUSTODIAN) SYSTEM. IF YOU HOLD THE SHARES IN STREET NAME, YOU WILL NEED TO INSTRUCT THE ACCOUNT EXECUTIVE AT YOUR BANK OR BROKER TO WITHDRAW THE SHARES FROM YOUR ACCOUNT IN ORDER TO EXERCISE YOUR REDEMPTION RIGHTS.

Subject to the foregoing, the approval of the Extension Amendment Proposal requires a special resolution under Cayman Islands law, being the affirmative vote of at least a two-thirds (2/3) majority of the votes cast by the holders of Class A Ordinary Shares and Class B Ordinary Shares voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the Shareholder Meeting.

Approval of the Adjournment Proposal requires an ordinary resolution under Cayman Islands law, being the affirmative vote of at least a majority of the votes cast by the holders of the issued Ordinary Shares, voting as a single class, who are present in person or represented by proxy and entitled to vote thereon, and who vote thereon, at the Shareholder Meeting. The Adjournment Proposal will only be put forth for a vote if there are not sufficient votes to approve the Extension Amendment Proposal at the Shareholder Meeting or if the Board has determined it otherwise necessary.

On January 16, 2024, Constellation voluntarily delisted its Class A Ordinary Shares, redeemable warrants, each one whole warrant exercisable for one Class A Ordinary Share at an exercise price of $11.50 (the “Warrants”), and units, each consisting of one Class A Ordinary Share and one-third of one redeemable warrant (the “Units” and together with the Ordinary Shares and the Warrants, the “Securities”), from the New York Stock Exchange and

began trading its Securities on the over-the-counter market. The Class A Ordinary Shares are currently quoted on the OTCID under the trading symbol “CSTAF,” the Warrants are currently quoted on the OTCID under the trading symbol “CSTWF” and the Units are currently quoted on the OTCID under the trading symbol “CSTUF.”

Constellation remains subject to the periodic reporting requirements of the U.S. Securities Exchange Act of 1934, as amended.

Record holders of Ordinary Shares at the close of business on December 30, 2025 (the “Record Date”) are entitled to vote or have their votes cast at the Shareholder Meeting. On the Record Date, there were 7,664,302 issued and outstanding Class A Ordinary Shares and 150,000 issued and outstanding Class B Ordinary Shares. Constellation’s Warrants do not have voting rights.

The Sponsor intends to vote all of its Ordinary Shares in favor of the proposals being presented at the Shareholder Meeting. The Initial Shareholders’ shares will be excluded from the pro rata calculation used to determine the per-share redemption price. As of the date of the accompanying proxy statement, the Sponsor holds approximately 97.7% of the issued and outstanding Ordinary Shares and Constellation’s officers and directors have not purchased any Public Shares, but may do so at any time. As a result, in addition to the Sponsor, the approval of the Extension Amendment Proposal and the Adjournment Proposal will not require the affirmative vote of any of the Ordinary Shares held by public shareholders.

The accompanying proxy statement contains important information about the Shareholder Meeting, the Extension Amendment Proposal and the Adjournment Proposal. Whether or not you plan to attend the Shareholder Meeting, Constellation urges you to read this material carefully and vote your shares.

The accompanying proxy statement is dated January 15, 2026, and is first being mailed to shareholders on or about that date.

By Order of the Board of Directors of Constellation Acquisition Corp I

/s/ Chandra R. Patel

Chandra R. Patel

Chairman of the Board of Directors