Investment in Unconsolidated Affiliates and Related Party Transactions

On March 14, 2013, OGE Energy entered into a Master Formation Agreement with the ArcLight group and CenterPoint Energy, Inc., pursuant to which OGE Energy, the ArcLight group and CenterPoint Energy, Inc., agreed to form Enable Midstream Partners to own and operate the midstream businesses of OGE Energy and CenterPoint that will initially be structured as a private limited partnership. This transaction closed on May 1, 2013.

Pursuant to the Master Formation Agreement, OGE Energy and the ArcLight group indirectly contributed 100 percent of the equity interests in Enogex LLC to Enable Midstream Partners. Enogex LLC is a provider of integrated natural gas midstream services. Enogex LLC is engaged in the business of gathering, processing, transporting and storing natural gas. Most of Enogex LLC's natural gas gathering, processing, transportation and storage assets are strategically located in the Arkoma and Anadarko basins of Oklahoma and the Texas Panhandle. CenterPoint Energy Field Services, LLC, a Delaware limited liability company that provides natural gas gathering and processing services for certain natural gas fields in the Mid-continent region of the United States and wholly owned subsidiary of CenterPoint, was converted into a Delaware limited partnership that became Enable Midstream Partners. CenterPoint contributed to Enable Midstream Partners its equity interests in each of (i) CenterPoint Energy Gas Transmission Company, LLC, a Delaware limited liability company that is an interstate pipeline that provides natural gas transportation, storage and pipeline services to customers principally in Arkansas, Louisiana, Oklahoma and Texas, (ii) MRT, a Delaware limited liability company that is an interstate pipeline that provides natural gas transportation, storage and pipeline services to customers principally in Arkansas, Illinois and Missouri and (iii) certain of its other midstream subsidiaries and caused its subsidiary CenterPoint Energy Southeastern Pipelines Holding, LLC to contribute a 24.95 percent interest in Southeast Supply Header, LLC, a Delaware limited liability company. CenterPoint indirectly owned a 50 percent interest in Southeast Supply Header, LLC, which owns a 1.0 billion cubic feet per day, 274-mile interstate pipeline that runs from the Perryville Hub in Louisiana to Coden, Alabama.

Immediately prior to closing, on May 1, 2013, the ArcLight group contributed $107.0 million and OGE Energy contributed $9.1 million to Enogex LLC in order to pay down short-term debt. At June 30, 2013, OGE Energy holds 28.5 percent of the limited partners interests in Enable Midstream Partners.

CenterPoint has certain put rights, and Enable Midstream Partners has certain call rights, exercisable with respect to any interest in Southeast Supply Header, LLC retained by CenterPoint following the formation of Enable Midstream Partners, under which CenterPoint would contribute to Enable Midstream Partners CenterPoint's retained interest in Southeast Supply Header, LLC at a price equal to the fair market value of such interest at the time the put right or call right is exercised. If CenterPoint were to exercise such put right or Enable Midstream Partners were to exercise such call right, CenterPoint's retained interest in Southeast Supply Header, LLC would be contributed to Enable Midstream Partners in exchange for consideration consisting of a specified number of limited partnership units and, subject to certain restrictions, a cash payment, payable either from CenterPoint to Enable Midstream Partners or from Enable Midstream Partners to CenterPoint, in an amount such that the total consideration exchanged is equal in value to the fair market value of the contributed interest in Southeast Supply Header, LLC.

The general partner of Enable Midstream Partners is equally controlled by CenterPoint and OGE Energy, who each have 50 percent of the management rights. CenterPoint and OGE Energy also own a 40 percent and 60 percent interest, respectively, in any incentive distribution rights to be held by the general partner of Enable Midstream Partners following an initial public offering of Enable Midstream Partners. In addition, for a period of time, the ArcLight group will have certain protective rights and approval rights over certain material activities of Enable Midstream Partners, including material increases in capital expenditures and certain equity issuances, entering into transactions with related parties and acquiring, pledging or disposing of certain material assets. The general partner of Enable Midstream Partners will initially be governed by a board made up of an equal number of representatives designated by each of CenterPoint Energy, Inc. and OGE Energy. Based on the 50/50 management ownership, with neither company having control, effective May 1, 2013, OGE Energy deconsolidated its interest in Enogex Holdings LLC and began accounting for its interest in Enable Midstream Partners using the equity method of accounting.

Pursuant to a Registration Rights Agreement dated as of May 1, 2013, OGE Energy and CenterPoint Energy, Inc. agreed to initiate the process for the sale of an equity interest in Enable Midstream Partners in an initial public offering. Enable Midstream Partners has agreed to file a registration statement for the initial public offering no later than May 1, 2014 and, subject to limited exceptions, consummate the initial public offering within 180 days of the filing of the registration statement. The Company currently expects that Enable Midstream Partners will file a registration statement during the fourth quarter of 2013. The initial public offering is subject to market conditions and OGE Energy can give no assurances that the initial public offering will be consummated.

Effective May 1, 2013, Enable Midstream Partners entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.

Subject to the exceptions provided below, pursuant to the terms of an Omnibus Agreement dated as of May 1, 2013 among OGE Energy, the ArcLight group and CenterPoint Energy, Inc., each of OGE Energy and CenterPoint Energy, Inc. will be required to hold or otherwise conduct all of its respective Midstream Operations (as defined below) located within the United States in Enable Midstream Partners. This restriction will cease to apply to both OGE Energy and CenterPoint Energy, Inc. as soon as either OGE Energy or CenterPoint Energy, Inc. ceases to hold (i) any interest in the general partner of Enable Midstream Partners or (ii) at least 20 percent of the limited partner interests of Enable Midstream Partners. "Midstream Operations" generally means, subject to certain exceptions, the gathering, compression, treatment, processing, blending, transportation, storage, isomerization and fractionation of crude oil and natural gas, its associated production water and enhanced recovery materials such as carbon dioxide, and its respective constituents and the following products: methane, NGLs (Y-grade, ethane, propane, normal butane, isobutane and natural gasoline), condensate, and refined products and distillates (gasoline, refined product blendstocks, olefins, naphtha, aviation fuels, diesel, heating oil, kerosene, jet fuels, fuel oil, residual fuel oil, heavy oil, bunker fuel, cokes, and asphalts), to the extent such activities are located within the United States.

In addition, if OGE Energy or CenterPoint Energy, Inc. acquires any assets or equity of any person engaged in Midstream Operations with a value in excess of $50 million (or $100 million in the aggregate with such party's other acquired Midstream Operations that have not been offered to Enable Midstream Partners), the acquiring party will be required to offer Enable Midstream Partners the opportunity to acquire such assets or equity for such value; provided, that the acquiring party will not be obligated to offer any such assets or equity to Enable Midstream Partners if the acquiring party intends to cease using them in Midstream Operations within 12 months. If Enable Midstream Partners does not exercise its option, then the acquiring party will be free to retain and operate such Midstream Operations; provided, however, that if the fair market value of such Midstream Operations is greater than 66 2/3 percent of the fair market value of all of the assets being acquired in such transaction, then the acquiring party will be required to dispose of such Midstream Operations within 24 months.

As long as the ArcLight group has certain protective rights, the ArcLight group will be prohibited from pursuing any transaction independently from Enable Midstream Partners (i) if the ArcLight group's consent is required for Enable Midstream Partners to pursue such transaction and (ii) the ArcLight group affirmatively votes not to consent to such transaction.

On May 1, 2013, OGE Energy, OGE Holdings and Enable Midstream Partners entered into a Seconding Agreement. During the term of the Seconding Agreement, OGE Holdings' employees will continue to perform services for Enable Midstream Partners and its subsidiaries.

Related Party Transactions

As OGE Energy's interest in Enogex Holdings was deconsolidated on May 1, 2013, operating costs charged between the Company and its affiliate, Enable Midstream Partners, after May 1, 2013, which were previously eliminated in consolidation, are discussed below.

OGE Energy charged operating costs to the Enogex Holdings/Enable Midstream Partners of $7.9 million and $14.6 million during the three and six months ended June 30, 2013, respectively. OGE Energy charges operating costs to its subsidiaries and unconsolidated affiliates based on several factors. Operating costs directly related to specific subsidiaries and unconsolidated affiliates are assigned to those subsidiaries and unconsolidated affiliates. Where more than one subsidiary or unconsolidated affiliate benefits from certain expenditures, the costs are shared between those subsidiaries and unconsolidated affiliates receiving the benefits. Operating costs incurred for the benefit of all subsidiaries and unconsolidated affiliates are allocated among the subsidiaries and unconsolidated affiliates, either as overhead based primarily on labor costs or using the "Distrigas" method. The Distrigas method is a three-factor formula that uses an equal weighting of payroll, net operating revenues and gross property, plant and equipment. OGE Energy adopted the Distrigas method in January 1996 as a result of a recommendation by the OCC Staff. OGE Energy believes this method provides a reasonable basis for allocating common expenses.

As OGE Energy's interest in Enogex Holdings was deconsolidated on May 1, 2013, related party transactions between the Company and its affiliate, Enable Midstream Partners, after May 1, 2013, which were previously eliminated in consolidation, are discussed below.



	Two Months Ended
	June 30,
(In millions)	2013
Operating Revenues:
Electricity to power electric compression assets	$	1.3
Cost of Goods Sold:
Natural gas transportation services	$	5.8
Natural gas storage services	2.3
Natural gas purchases (A)	2.5


(A)	At June 30, 2013, there was $1.2 million of natural gas purchases recorded for these activities.

Summarized Financial Information of Enable Midstream Partners

As Enable Midstream Partners began operations on May 1, 2013, summarized unaudited financial information for 100 percent of Enable Midstream Partners is presented below at June 30, 2013 (at historical cost) and for the two months ended June 30, 2013. Fair value information for Enable Midstream Partners' information below is not currently available; however, OGE Holdings expects these fair value amounts to be available by the end of the third quarter of 2013.



Balance Sheet	June 30, 2013
	(In millions)
Current assets	$	393.9
Non-Current assets	8,209.2
Current liabilities	379.6
Non-Current liabilities	2,249.1



	Two Months Ended
Income Statement	June 30, 2013
	(In millions)
Operating revenues	$	502.0
Gross margin	207.4
Operating expenses	132.4
Net income	65.1

Enable Midstream Partners concluded that the formation of Enable Midstream Partners was considered a business combination, and CenterPoint was the acquirer of Enogex Holdings for accounting purposes. Under this method, the fair value of the consideration paid by CenterPoint for Enogex Holdings is allocated to the assets acquired and liabilities assumed on May 1, 2013 based on their fair value. Enogex Holdings' assets, liabilities and equity will accordingly be adjusted to estimated fair value as of May 1, 2013. Determining the fair value of certain assets and liabilities assumed is judgmental in nature and often involves the use of significant estimates and assumptions. Enable Midstream Partners is using appraisers to assist in the determination of fair value of certain assets. Enable Midstream Partners' valuation is expected to be finalized in the third quarter of 2013. OGE Energy does not expect that its estimated equity in earnings of Enable Midstream Partners in the second quarter of 2013 will be materially different as a result of the fair value determination.