The board that manages a big chunk of the Canada Pension Plan's assets has further diversified its investments by placing more than half a billion dollars in the U.S. real estate market.

The CPP Investment Board (CPPIB) is investing $500 million US in partnership with TIAA-CREF Asset Management — a huge U.S. retirement fund that has extensive U.S. real estate holdings.

The board said it's joining with the U.S. fund to place $300 million US in a portfolio of U.S. office properties. "The investment focus is on strategic acquisitions of partially leased office properties in stable or recovering metropolitan areas with at least 500,000 residents," a CPPIB statement said.

Another $200 million US is going into a partnership that invests in institutional-quality U.S. real estate assets.

"We are pleased to partner with TIAA-CREF Asset Management which is a knowledgeable, long-term investor in the U.S. real estate market," said Graeme Eadie, a senior vice president at the CPP Investment Board.

"Our investment significantly increases our exposure in the U.S. real estate market, which supports our focus of diversifying the overall CPP Investment Board portfolio by product type and geography."

The CPPIB invests funds that are not immediately needed by the CPP to pay current benefits. The CPP fund is currently worth more than $110 billion. About $5 billion of that is in commercial real estate — mainly in Canada, with smaller commitments in the U.S. and western Europe.