Williams Cos. Inc.'s private equity partners are planning to exit the company's midstream venture with them through a sale of their minority stake, expected to be worth $750 million to $1 billion, Reuters reported March 10.

EnCap Flatrock Midstream and Oaktree Capital Group LLC are said to have enlisted the services of Barclays Plc and Citigroup Inc. in selling their minority investment in Caiman Energy II, a midstream venture with Williams as the majority owner, the report said, citing people "familiar with the matter." The sale negotiations are currently ongoing, the sources said.

Caiman Energy II has a 50% stake in Blue Racer Midstream LLC, a joint venture formed in 2012 that operates a pipeline network carrying natural gas in the Marcellus and Utica shale plays. The other half of the $1.5 billion joint venture is owned by Dominion Energy Inc.