2 investors.centerpointenergy.com March 2013 oge.com/investor-relations Forward Looking Statement This document does not constitute an offer to sell or a solicitation of an offer to buy any securities described herein, nor shall there be any sale of such securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. Any such offering may be made only by means of a prospectus. This document includes forward-looking statements. Actual events and results may differ materially from those projected. The statements in this document regarding the anticipated closing of the partnership formation, including the anticipated benefits and a possible initial public offering of the partnership, and other statements that are not historical facts are forward-looking statements. Each forward looking statement contained in this document speaks only as of the date of this document. Factors that could affect actual results include the satisfaction or waiver of the conditions to closing the transaction, the receipt of applicable regulatory approvals and the termination rights of the parties under the master formation agreement for the transaction, and other factors discussed in CenterPoint Energy’s and its subsidiaries’ and OGE Energy Corp.’s Form 10-Ks for the fiscal year ended December 31, 2012, and other filings with the SEC. Pursuant to a registration rights agreement to be entered into upon the closing of the transaction, OGE and CenterPoint Energy will agree to initiate the process for the sale of an equity interest in the Midstream Partnership in an initial public offering (IPO) after formation. The parties can give no assurances that the IPO will be consummated. Prior to consummating the IPO, OGE, CenterPoint Energy and the partnership will determine the financial and other terms of the offering in conjunction with ArcLight. In addition, consummation of the IPO is subject to market conditions. | 
