The Toronto-based pension fund manager will own a 45 percent stake in the joint venture. Health Care REIT, which is selling the assets into the venture, will own the remaining 55 percent.

"This acquisition marks our entry into the health care real estate sector, a growing and compelling sub-sector within the real estate market," Peter Ballon, CPPIB head of real estate investments in the Americas, said in a statement. "With an aging population and increasing demand for health care, we view the U.S. health care real estate sector as an attractive long-term investment."

The portfolio, valued at $449 million, consists of medical office buildings in and around Beverly Hills, San Diego and Los Angeles.

(Reporting by Euan Rocha; Editing by Chizu Nomiyama)