An ArcLight Capital Partners LLC affiliate will acquire a 9.9-percent equity ownership stake in Enogex, OGE Energy Corp.'s midstream natural gas pipeline subsidiary, for $183 million. As part of the transaction, OGE Energy will contribute its marketing business, OGE Energy Resources Inc., to Enogex. The transaction is expected to be completed by Nov. 1.

"Enogex's strong operating capabilities combined with the additional funding to be provided by ArcLight should accelerate the expansion of our natural gas midstream business," said Pete Delaney, OGE Energy chairman, president and CEO.

The transaction will enable ArcLight to increase its ownership stake over time by providing equity funding for Enogex capital expenditures.