A unit of Power Corp. of Canada has acquired a mutual fund company from Marsh & McLennan Companies Inc.

Great-West Lifeco Inc., Winnipeg, paid Marsh, New York, $3.9 billion in cash for Putnam Investments, Boston.

Power Financial Corp., a financial services arm of Power Corp., Montreal, is Great-West’s parent.

“We are very excited to join Great-West Lifeco and the Power Financial Corp. group of companies,” Putnam President Charles Haldeman Jr. says in a statement. “They understand our business, have a long-term view and are financially very strong.”

Putnam was founded in 1937. It now has $121 billion in mutual fund assets under management and $72 billion in institutional assets under management.