Blackstone (NYSE: BX) announced Feb. 23 the commencement of the investment period for its second energy-focused private equity fund, Blackstone Energy Partners II (BEP II), with total commitments of $4.5 billion.

The New York-based firm said BEP II received significant interest from both existing and new investors, with demand well surpassing the fund’s $4.5 billion hard cap.

Like its predecessor fund BEP I, a $2.4 billion fund that had its final close in September 2012, BEP II will invest in control-oriented equity and equity-linked interests in companies, assets and development projects in the energy and natural resources sector on a global basis.

To date, Blackstone’s energy-focused private equity team of professionals has deployed more than $8 billion in this strategy, the firm said. Blackstone's $16 billion diversified global private equity fund will continue to invest alongside BEP II in energy transactions on a 50/50 basis.

David Foley, senior managing director and CEO of Blackstone Energy Partners, said in a statement, “Following on the strong performance of BEP I, we could not be more pleased with the exceptionally positive reception BEP II received. We deeply appreciate the confidence that our investors have placed in us by entrusting us to continue to deliver excellent returns for the millions of workers and retirees they represent. Looking forward, we believe that our experienced team, deep network of relationships with talented industry executives, patient capital and proven strategy positions us uniquely well to take full advantage of the significant recent cyclical downturn in oil and gas prices.”

Investors in BEP II include a diverse group of U.S. state pension funds, corporate pension funds, sovereign wealth funds, insurance companies, endowments, foundations and family offices.