Energy & Minerals Group, a Houston private equity firm, says it has raised approximately $2 billion to date for its latest investment fund and plans to increase the fund to $3 billion. The fund currently has about $4.5 billion in assets under management.

The firm is one of the largest private equity investors in natural resources worldwide, and is a participant in around $12 billion in energy projects and mineral-related projects internationally.

With many public capital providers still holding back in the public market, private equity investors in Texas, New York, and elsewhere have stepped forward to fill the vacuum, according to analysts. The upstream and midstream segments of the oil and gas industry have been major beneficiaries of these investments, including companies involved in capital-intensive shale development and offshore exploration and production.