Private equity firm The Blackstone Group Inc. in an April 29 SEC filing reported holding a 6.9% interest in pipeline company Energy Transfer LP.

Blackstone said the 6.9% interest, which would be the second-largest stake in the company after Energy Transfer CEO Kelcy Warren's stake, comprises units held by Harvest Fund Advisors LLC, Bloomberg News reported April 29.

In 2017, Blackstone moved to acquire Harvest, thereby expanding its midstream gas and oil holdings. In March 2019, Blackstone's Harvest was the biggest buyer of Energy Transfer shares as it purchased 71.9 million units of the midstream partnership.

In mid-April, Blackstone's infrastructure arm Blackstone Infrastructure Partners closed its previously announced merger transaction with Tallgrass Energy LP, which is also a pipeline company.

Dallas, Texas-based Energy Transfer is a limited partnership with operations that include natural gas midstream transportation and storage assets, among other services.