Assets of Discovery, located in Colorado's Denver-Julesburg Basin, include a 60 million cubic feet per day (MMcf/d) gas processing plant, with an extra 200 MMcf/d plant that is under construction and is expected to be in service by the end of 2018, KKR said.

KKR will own 60 percent stake in Discovery and the remaining will be held by Williams upon close of the deal, expected in the third quarter of this year. Discovery will continue to be led by its existing management.

Williams will also fund additional capital, when required, to bring its total ownership of Discovery to 50 percent.

KKR said it will fund the deal primarily through its energy and infrastructure funds.

Last year, TPG Growth, a sister company of asset management firm TPG, bought Dallas, Houston-based oil and gas producer Discovery Midstream.

Separately, privately-held Harvest Midstream Company said it would buy Williams Partners LP pipeline and storage assets in Colorado and New Mexico for $1.13 billion.

(Reporting by Anirban Paul in Bengaluru; Editing by Shounak Dasgupta and Shailesh Kuber)