UPDATE 1-OGE, ETP to form natural gas asset partnership

(Adds details, background on master limited partnerships)

NEW YORK, Sept 23 (Reuters) - OGE Energy Corp (OGE.N) and Energy Transfer Partners LP (ETP.N) said they would put their natural gas assets together in a joint venture to create a master limited partnership.

OGE will contribute its Enogex midstream assets, which include its natural gas gathering lines, 2,300 miles of transportation pipelines and two storage facilities.

Energy Transfer Partners will contribute its Transwestern Pipeline Co, ETC Canyon Pipeline and its 50 percent stake in Midcontinent Express Pipeline.

The companies will launch a public offering of the business after the creation of the MLP.

Energy companies have long used MLPs to house assets that generate steady cash flow, such as pipelines and midstream gas properties, since they pay out nearly all their operating cash flows to investors and provide tax advantages to corporations.

The new venture, to be called ETP Enogex Partners, will initially be led by an executive management team including OGE Chairman and Chief Executive Pete Delaney and ETP Chairman and Chief Executive Kelcy Warren, as well as the chief operating officers from both companies.

OGE was advised by UBS Investment Bank and ETP by Credit Suisse. (Reporting by Matt Daily; Editing by Lisa Von Ahn)