Riverstone Holdings LLC is investing as much as $300 million in Carrier Energy Partners LLC.
Sugar Land, Texas-based Carrier acquires and develops upstream oil and gas assets.
Riverstone, a private equity firm based in New York, focuses on energy. The firm raised about $26 billion in equity capital since it was founded in 2000.
Riverstone closed a $7.7 billion
energy fund in June. In July, it teamed up with Bridger LLC to invest up to $300 million in the oil company. Before that, in April, Riverstone invested $200 million in Ridgebury Tankers LLC, which operates tankers.