Post Oak Energy Capital LP has closed on its fourth fund after gaining $600 million from investors, the company said on Nov. 13.

Post Oak Energy Partners IV will pursue the same strategy as the company’s three other funds, with equity investments in North American oil and gas companies, oilfield services and related infrastructure.

Funding from Post Oak will continue to be used for growth capital, development acceleration, acquisitions and recapitalization purposes.

Post Oak Energy Partners III LP continues to have available new investment capacity and Post Oak expects to begin investing capital from the fourth fund in early 2018.

Post Oak has invested in 25 companies since forming its first fund in late 2011, primarily focused on upstream oil and gas investments, with two oilfield services and two midstream investments.

Willkie Farr & Gallagher LLP represented Post Oak Energy Capital in the transaction, which was led by partners Phillip Isom and Bruce Herzog.