Bleichroeder Acquisition Corp. III

As filed with the U.S. Securities and Exchange Commission on June 18, 2026.

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

1345 Avenue of the Americas, Fl 47

New York, NY 10105

212-984-3835

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Marcello Padula

Chief Executive Officer

1345 Avenue of the Americas, Fl 47

New York, NY 10105

212-984-3835

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after the effective date of this registration statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933 check the following box.☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act.☐

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

$300,000,000

30,000,000 Units

––––––––––––––––––––––––

Bleichroeder Acquisition Corp. III is a blank check company incorporated as a Cayman Islands exempted company and formed for the purpose of effecting a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses, which we refer to throughout this prospectus as our initial business combination. We have not selected any business combination target, and we have not, nor has anyone on our behalf, initiated any substantive discussions, directly or indirectly, with any business combination target. While we may pursue an initial business combination in any industry, sector or geographic region, we intend to focus our efforts on North American and European businesses in disruptive growth sectors, which are sectors our management team believes are being transformed via technology adoption, and where we believe our management team’s operational and investment expertise will provide us with a competitive advantage.

This is an initial public offering of our securities. Each unit has an offering price of $10.00 and consists of one Class A ordinary share and one-fourth of one redeemable warrant. Each whole warrant entitles the holder thereof to purchase one Class A ordinary share at a price of $11.50 per share, subject to adjustment as described herein. Only whole warrants are exercisable. No fractional warrants will be issued upon separation of the units and only whole warrants will trade. The warrants will become exercisable 30 days after the completion of our initial business combination, and will expire five years after the completion of our initial business combination or earlier upon redemption or our liquidation, as described herein. The underwriters have a 45-day option from the date of this prospectus to purchase up to an additional 4,500,000 units to cover over-allotments, if any.

We will provide our public shareholders with the opportunity to redeem, regardless of whether they abstain, vote for, or vote against, our initial business combination, all or a portion of their Class A ordinary shares that were sold as part of the units in this offering, which we refer to collectively as our public Class A ordinary shares, upon the completion of our initial business combination at a per-share price, payable in cash, equal to the aggregate amount then on deposit in the trust account described below as of two business days prior to the consummation of our initial business combination, including interest earned on the funds held in the trust account (net of amounts withdrawn to pay our taxes, if any), divided by the number of then outstanding public shares, subject to the limitations and on the conditions described herein. The proceeds placed in the trust account and the interest earned thereon shall not be used to pay for possible excise tax or any other fees or taxes that may be levied on us on any redemptions or share buybacks by us pursuant to any current, pending or future rules or laws, including without limitation any excise tax due under the Inflation Reduction Act of 2022. See “Summary — The Offering — Redemption rights for public shareholders upon completion of our initial business combination” on page 36 and“Summary — The Offering — Redemption of public shares and distribution and liquidation if no initial business combination” on page 42 for more information.

Notwithstanding the foregoing redemption rights, if we seek shareholder approval of our initial business combination and we do not conduct redemptions in connection with our initial business combination pursuant to the tender offer rules, our amended and restated memorandum and articles of association provide that a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% of the shares sold in this offering without our prior consent. However, we would not be restricting our shareholders’ ability to vote all of their shares (including all shares held by those shareholders that hold more than 15% of the shares sold in this offering) for or against our initial business combination. See“Summary — The Offering — Limitation on redemption rights of shareholders holding 15% or more of the shares sold in this offering if we hold shareholder vote” on page 40 for further discussion on certain limitations on redemption rights.

Our sponsor, Bleichroeder Sponsor 3 LLC and Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC (“CCM”), the representative of the underwriters, have committed, pursuant to written agreements, to purchase from us an aggregate of 8,500,000 private placement warrants (whether or not the underwriters’ over-allotment

option is exercised in full) at a price of $1.00 per warrant, for an aggregate purchase price of $8,500,000 (whether or not the underwriters’ over-allotment option is exercised in full) in a private placement that will close simultaneously with the closing of this offering.

Of those 8,500,000 private placement warrants, our sponsor has agreed to purchase 5,000,000 private placement warrants and CCM has agreed to purchase 3,500,000 private placement warrants. The private placement warrants are identical to the warrants sold as part of the units sold in this offering, subject to certain limited exceptions as described in this prospectus.

Our sponsor has purchased an aggregate of 11,500,000 Class B ordinary shares (up to 1,500,000 of which are subject to surrender to us for no consideration depending on the extent to which the underwriters’ over-allotment option is exercised) for an aggregate purchase price of $25,000, or approximately $0.002 per share. The Class B ordinary shares will automatically convert into Class A ordinary shares at the time of our initial business combination, or at any time prior thereto at the option of the holder thereof, on a one-for-one basis, subject to adjustment as provided herein. In the case that additional Class A ordinary shares, or equity-linked securities (as described herein), are issued or deemed issued in excess of the amounts issued in this offering and related to the closing of our initial business combination, the ratio at which the Class B ordinary shares will convert into Class A ordinary shares will be adjusted (unless the holders of a majority of the issued and outstanding Class B ordinary shares agree to waive such anti-dilution adjustment with respect to any such issuance or deemed issuance) so that the number of Class A ordinary shares issuable upon conversion of all Class B ordinary shares will equal, in the aggregate, approximately 25% of the sum of (i) all ordinary shares issued and outstanding upon the completion of this offering (including any Class A ordinary shares issued pursuant to the underwriters’ over-allotment option and excluding the Class A ordinary shares underlying the private placement warrants issued to the sponsor), plus (ii) all Class A ordinary shares and equity-linked securities issued or deemed issued in connection with the closing of the initial business combination (subject to certain exclusions described herein) minus (iii) any redemptions of Class A ordinary shares by public shareholders in connection with an initial business combination, and any shares or equity-linked securities issued, or to be issued, to any seller in the business combination and in connection with any amendment to our amended and restated memorandum and articles of association made prior to the consummation of the initial business combination (A) to modify the substance or timing of our obligation to allow redemption in connection with our initial business combination or to redeem 100% of our public shares if we do not complete our initial business combination within the completion window or (B) with respect to any other material provisions relating to the rights of holders of Class A ordinary shares or pre-business combination activity; provided that such conversion of founder shares will never occur on a less than one-for-one basis. Additionally, our public shareholders may experience material dilution from the exercise of the 8,500,000 private placement warrants to be purchased by our sponsor and CCM simultaneously with the closing of this offering, as well as from the conversion of any working capital loans into private placement warrants, if elected by the sponsor. The cashless exercise of the private placement warrants, including private placement warrants upon conversion of working capital loans, along with the public warrants under the circumstances specified in the warrant agreement as described herein, may result in material dilution to our public shareholders. If we increase or decrease the size of the offering, we will effect a share capitalization or a share repurchase or redemption or other appropriate mechanism, as applicable, with respect to our Class B ordinary shares immediately prior to the consummation of the offering in such amount as to maintain the ownership of founder shares by our initial shareholders, on an as-converted basis, at approximately 25% of our issued and outstanding ordinary shares upon the consummation of this offering. Such dilution could materially increase to the extent that the anti-dilution provision of the founder shares results in the issuance of Class A ordinary shares on a greater than one-to-one basis upon conversion of the founder shares at the time of the closing of our initial business combination to maintain the number of founder shares at approximately 25% (as described above). Prior to, or in connection with, the closing of our initial business combination, only holders of our Class B ordinary shares (i) will have the right to vote to appoint and remove directors prior to or in connection with the completion of our initial business combination and (ii) will be entitled to vote on continuing our company in a jurisdiction outside the Cayman Islands (including any special resolution required to amend our constitutional documents or to adopt new constitutional documents, in each case, as a result of our approving a transfer by way of continuation in a jurisdiction outside the Cayman Islands). On any other matters submitted to a vote of our shareholders prior to or in connection with the completion of our initial business combination, holders of the Class B ordinary shares and holders of the Class A ordinary shares will vote together as a single class, except as required by law. Upon consummation of this offering or thereafter, we will repay up to $500,000 in loans made to us by our sponsor to cover offering-related and organizational expenses. Additionally, we will reimburse the managing member of our Sponsor an amount equal to $5,000 per month for office space, utilities and secretarial and administrative support made available to us, as described elsewhere in this prospectus. In the event that following this offering we obtain working capital loans from our sponsor to finance transaction costs related to our initial business combination, up to $2,000,000 of such loans may be convertible into

private placement warrants of the post-business combination entity at a price of $1.00 per warrant at the option of our sponsor, and the exercise of such warrants may result in material dilution to our public shareholders. Additionally, our sponsor, our officers and directors or their affiliates may be paid finder’s fees, advisory fees, consulting fees or success fees in order to effectuate the completion of our initial business combination. Additionally, following consummation of a business combination, members of our management team will be entitled to reimbursement for any out-of-pocket expenses related to identifying, investigating and completing an initial business combination. Our Chief Executive Officer will receive an indirect interest in 350,000 founder shares and our Chief Financial Officer will receive an indirect interest in 200,000 founder shares through membership interests in our sponsor. Each of our directors will also receive for his or her service as a director an indirect interest in 10,000 founder shares through membership interests in our sponsor.

Upon consummation of this offering, we will pay MJP Advisory Group LLC, an affiliate of our Chief Executive Officer (“MJP Advisory”) $18,000 per month plus out-of-pocket expenses for his services as Chief Executive Officer, pursuant to an advisory agreement; upon completion of our initial business combination or our liquidation, an amount equal to $600,000 less the total amount of all such monthly payments made up to that time shall be payable under such agreement, as further described in this prospectus; prior to our initial business combination, no payments under this agreement shall be made from amounts held in the trust account. As a result, there may be actual or potential material conflicts of interest between our sponsor, its affiliates and promoters on the one hand, and purchasers in this offering on the other hand. The sponsor’s 10,000,000 Class B ordinary shares, assuming forfeiture, will represent 25% of all ordinary shares outstanding immediately following the consummation of the offering, assuming that the underwriters’ over-allotment option is not exercised. As a result, there may be actual or potential material conflicts of interest between members of our management team, our sponsor, its affiliates and promoters on one hand, and purchasers in this offering on the other. See “Summary — The Offering — Our Sponsor” on page 9; “Summary — The Offering — Transfer restrictions on founder shares” on page 27, “Summary — The Offering — Founder shares conversion and anti-dilution rights” on page 27, “Summary — The Offering — Appointment and removal of directors and continuing the company outside of the Cayman Islands; voting rights” on page 28, “Risk Factors — Risks Relating to our Management Team — The nominal purchase price paid by our sponsor for the founder shares may result in significant dilution to the implied value of your public shares upon the consummation of our initial business combination” on page 86, “— Risks Relating to our Securities — We may issue additional ordinary shares or preference shares to complete our initial business combination or under an employee incentive plan after completion of our initial business combination. We may also issue Class A ordinary shares upon the conversion of the Class B ordinary shares at a ratio greater than one-to-one at the time of the closing of our initial business combination as a result of the anti-dilution provisions contained in our amended and restated memorandum and articles of association. Any such issuances would dilute the interest of our shareholders and likely present other risks” on page 66 for further discussion on our sponsor’s and our affiliates’ securities.

As more fully discussed in “Management — Conflicts of Interest” on page 159, each of our officers and directors presently has, and any of them in the future may have additional, fiduciary, contractual or other obligations or duties to one or more other entities pursuant to which such officer or director is or will be required to present a business combination opportunity to such entities. The low price that our sponsor, executive officers and directors (directly or indirectly) paid for the founder shares creates an incentive whereby our officers and directors could potentially make a substantial profit even if we select an acquisition target that subsequently declines in value and is unprofitable for public shareholders. If we are unable to complete our initial business combination within the completion window, or by such earlier liquidation date as our board of directors may approve, the founder shares and private placement warrants (and the underlying securities) may expire worthless, except to the extent they receive liquidating distributions from assets outside the trust account, which could create an incentive for our sponsor, executive officers and directors to complete a transaction even if we select an acquisition target that subsequently declines in value and is unprofitable for public shareholders. Further, each of our officers and directors may have a conflict of interest with respect to evaluating a particular business combination if the retention or resignation of any such officers and directors was included by a target business as a condition to any agreement with respect to our initial business combination. As a result, there may be actual or potential material conflicts of interest between members of our management team, our sponsor, its affiliates and promoters on one hand, and purchasers in this offering on the other. See“Summary — Our Sponsor” on page 9, “Proposed Business — Sourcing of Potential Business Combination Targets” on page 130, “Certain Relationships and Related Party Transactions” on page 169,“Summary — Conflicts of Interest”, “Risk Factors — Risks Relating to our Search for, and Consummation of or Inability to Consummate, a Business Combination — Since our sponsor, officers and directors, any other holder of our founder shares, including the non-managing sponsor investor, may lose their entire investment in us if our initial business combination is not

completed (other than with respect to public shares they may acquire during or after this offering), a conflict of interest may arise in determining whether a particular business combination target is appropriate for our initial business combination.” and “Management — Conflicts of Interest”on page 159 for more information.

We have until the date that is 24 months from the closing of this offering or until such earlier liquidation date as our board of directors may approve, to consummate our initial business combination. If we anticipate that we may be unable to consummate our initial business combination within such 24-month period, we may seek shareholder approval to amend our amended and restated memorandum and articles of association to extend the date by which we must consummate our initial business combination. If we seek shareholder approval for an extension, each holder of public shares (who is not the Sponsor, a Founder, Officer or Director (as those terms are defined in the amended and restated memorandum and articles of association) will be offered an opportunity to redeem their public shares upon effectiveness of any such extension at a per share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, including interest earned thereon (which interest shall be net of taxes payable (other than Excise or similar taxes)), divided by the number of then issued and outstanding public shares, subject to applicable law. If we are unable to complete our initial business combination within 24 months from the closing of this offering (or such later date as approved by our shareholders), or by such earlier liquidation date as our board of directors may approve, we will redeem 100% of 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 thereon (less taxes payable (other than Excise or similar taxes) and less up to $100,000 of interest to pay dissolution expenses), divided by the number of then issued and outstanding public shares, subject to applicable law as further described herein.

Currently, there is no public market for our units, Class A ordinary shares or warrants. We intend to apply to have our units listed on The Nasdaq Global Market, or Nasdaq, under the symbol “BCCQU,” on or promptly after the date of this prospectus. We cannot guarantee that our securities will be approved for listing on Nasdaq. We expect the Class A ordinary shares and warrants comprising the units to begin separate trading on the 52 nd day following the date of this prospectus unless CCM, the representative of the underwriters, informs us of its decision to allow earlier separate trading, subject to our satisfaction of certain conditions as described further herein. Once the securities comprising the units begin separate trading, we expect that the Class A ordinary shares and warrants will be listed on Nasdaq under the symbols “BCCQ” and “BCCQW” respectively.

We are an “emerging growth company” and a “smaller reporting company” under applicable federal securities laws and will be subject to reduced public company reporting requirements. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 49 for a discussion of information that should be considered in connection with an investment in our securities. Investors will not be entitled to protections normally afforded to investors in Rule 419 blank check offerings.

Neither the U.S. Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

No offer or invitation, whether directly or indirectly, is being or may be made to the public in the Cayman Islands to subscribe for any of our securities.

(1) Includes $0.20 per unit (excluding any units sold pursuant to the underwriters’ option to purchase additional units), or $6,000,000 in the aggregate (whether or not the underwriters’ option to purchase additional units is exercised), payable to CCM upon the closing of this offering. Also includes $0.40 per unit on units other than those sold pursuant to the underwriters’ option to purchase additional units and $0.60 per unit on units sold pursuant to the underwriters’ option to purchase additional units, or up to $12,000,000 in the aggregate or up to $14,700,000 in the aggregate if the underwriters’ over-allotment option is exercised in full, payable to CCM for deferred underwriting commissions to be deposited into a U.S. based trust account and released to CCM for its own account only upon the completion of an initial business combination, but $0.40 per unit in deferred underwriting commissions on all units sold in this offering shall be due solely on amounts remaining in the trust account following all properly submitted shareholder redemptions in connection with the consummation of our initial business combination. See also “Underwriting” for a description of compensation and other items of value payable to the underwriters.

Of the proceeds we receive from this offering and the sale of the private placement warrants described in this prospectus, $300.0 million, or $345.0 million if the underwriters’ over-allotment option is exercised in full ($10.00 per unit in either case), will be placed into a U.S.-based trust account with Continental Stock Transfer & Trust Company acting as trustee.

The following table illustrates the difference between the public offering price per unit and our net tangible book value per share, as adjusted to reflect various potential redemption levels that may occur in connection with the closing of our initial business combination, which we refer to as “Adjusted NTBVPS,” on a pro forma basis to give effect to this offering and the issuance of the private placement warrants, assuming the exercise in full and no exercise of the over-allotment option. Adjusted NTBVPS excludes the effect of the consummation of our initial business combination or any related transactions or expenses. See “Dilution” on page 104 for more information.

Our sponsor and members of our management team will directly or indirectly own our securities following this offering, and accordingly, they may have a conflict of interest in determining whether a particular target business is an appropriate business with which to effectuate our initial business combination. Additionally, each of our officers and directors presently has, and any of them in the future may have additional, fiduciary, contractual or other obligations or duties to one or more other entities pursuant to which such officer or director is or will be required to present a business combination opportunity to such entities. As a result, there may be actual or potential material conflicts of interest between our sponsor and its affiliates and promoters on one hand, and purchasers in this offering on the other. See “Summary — The Offering — Conflicts of interest” on page 45, “Proposed Business — Sourcing of Potential Business Combination Targets” on page 130 and “Management — Conflicts of Interest” on page 159 for more information.

The underwriters are offering the units for sale on a firm commitment basis. The underwriters expect to deliver the units to the purchasers on or about , 2026.

Sole Book-Running Manager

Cohen & Company Capital Markets

, 2026