(Bloomberg) -- Manulife Financial, Canada’s largest life insurer, agreed to buy New York Life Insurance’s retirement plan services business in a deal that will boost assets under administration by about $50 billion.

Manulife’s U.S. unit, John Hancock Financial, will make the acquisition, the Toronto-based company said today in a statement. New York Life will reinsure -- or backstop -- a portion of John Hancock’s life-insurance policies. Terms of the deals weren’t disclosed.

Manulife Chief Executive Officer Donald Guloien has been expanding his company’s retirement-plan operations, which will administer about $135 billion in assets covering 2.5 million participants once the transaction announced today is completed in the first half of next year. In September, he struck a deal to buy Standard Life’s Canadian business for about C$4 billion ($3.4 billion).

“Manulife is a major player in the pensions business in Canada, the United States, Hong Kong and Indonesia,” Guloien said in the statement. “This transaction, similar to our recently announced acquisition of Standard Life’s Canadian operations, will significantly increase our retirement plans business.”

Under the reinsurance deal, New York Life will assume $7 billion of John Hancock’s liabilities on life policies, the U.S. company said a separate statement. It will get about $10.5 billion in new assets to manage. John Hancock will still pay claims and dividends to policyholders.

New York Life saw the transaction as a way to add high- quality life policies to its books, CEO Ted Mathas said in an e-mailed statement. The retirement-plan operation didn’t “flow naturally” from the life-insurance and asset management businesses, he said.

Manulife rose 1.2% to C$22.41 at 4:04 p.m. in Toronto. New York Life is owned by policyholders.

Read more: