Riverstone Holdings LLC is investing up to $300 million in Eagle Energy Exploration LLC.

Tulsa, Okla.-based Eagle is an oil and gas exploration company that focuses on the mid-continent region of the U.S.

Riverstone’s investment is made up of $200 million from Riverstone Global Energy and Power Fund V and up to $100 million from Riverstone Energy Ltd.

Riverstone is a Houston-based private equity firm that invests in the oil and gas sector. In October, the firm invested $200 million in Abaco Energy Technologies LLC, a company that focuses on manufacturing and services related to oil drilling. Also in October, Riverstone agreed to invest up to $300 million in Carrier Energy Partners LLC, which develops upstream oil and gas assets.