Manulife Financial Corp., Canada’s largest insurer, said its John Hancock unit reached a deal to acquire a broker-dealer and investment adviser firm from Symetra Financial Corp. to expand in the U.S.

Symetra Investment Services has about 280 registered representative and would become affiliated with the John Hancock Financial Network, Boston-based John Hancock said today in a statement. Terms weren’t disclosed.

Manulife is seeking to expand its asset-management businesses to boost profits. The Toronto-based insurer reached a deal in August to buy investment adviser Wellington West Financial Services Inc. from National Bank of Canada.

The Symetra advisers “offer us a breadth of wealth experience and a geographic presence that complements our existing footprint as we continue to grow,” Brian Heapps, president of John Hancock Financial Network, said in the statement.

Symetra, based in Bellevue, Washington, has gained 15 percent this year. Manulife has advanced 20 percent.