Canada Pension Plan Investment Board (CPPIB) said on Wednesday it would invest up to US$1 billion in a partnership with Encino Energy LLC to buy oil and gas assets in the United States.

The fund said the partnership, Encino Acquisition Partners, would focus on acquiring assets in mature basins.

Houston-based Encino Energy, which will operate the assets acquired by the partnership, has committed US$25 million.

CPPIB, Canada's biggest public pension fund, in March formed a JV to buy three U.S. student housing portfolios for about US$1.6 billion.