ONE Gas, Inc.

Solicitation of proxies will be primarily by mail and telephone. We have engaged Sodali & Co., 333 Ludlow Street, 5 th Floor, South Tower, Stamford, CT 06902, to solicit proxies for a fee of $11,500 plusout-of-pocket expenses. In addition, certain of our officers, directors and employees may solicit proxies on our behalf in person or by mail, telephone, fax or email, for which such persons will receive no additional compensation. We will pay all costs of soliciting proxies. We will also reimburse brokerage firms, banks and other custodians, nominees and fiduciaries for their reasonable expenses for forwarding proxy materials to our shareholders.