NEW YORK CITY-Kravis Roberts & Co. LP, a global investment firm led by Henry Kravis and George Roberts, has invested $4 billion in two funds dedicated to energy, infrastructure and natural resources as part of the company’s strategy to expand its footprint beyond private equity.

“There is a growing need for capital to support investment and growth in critical public and private infrastructure,” says Raj Agrawal and Jesus Olmos Clavijo, heads of North American and European Infrastructure at KKR, in a statement. “Given its long term and predictable cash flow, coupled with the growing need for investment, we continue to believe that infrastructure is an attractive, stable asset class.”

After already committing $1.3 billion to separate infrastructure accounts, KKR has now raised more than $1 billion for its infrastructure fund, which will target midstream energy, utilities, renewable energy, social infrastructure and transportation-related projects, totaling $2.4 billion altogether. In addition, the company has also closed its natural resource fund at $1.25 billion, which also includes $350 million of capital outside the fund, according to a statement.