(Bloomberg News) Sun Life Financial Inc., Canada's third-largest insurer, is seeking a buyer for a U.S. annuities business that may fetch more than $1 billion, said people with knowledge of the matter.

Morgan Stanley is helping Sun Life solicit bids and has attracted interest mostly from investment firms, including Guggenheim Partners LLC and a company run by U.K. investor Clive Cowdery, said the people, who asked not to be named because the talks are private. Sun Life may pick a suitor for exclusive talks within days, one of the people said.

Sun Life said in December that it would stop selling variable annuities and individual life insurance products in the U.S., shifting its focus to Canada and Asia. U.S. asset managers such as Guggenheim, Apollo Global Management LLC and Harbinger Capital Partners LLC have bought annuities operations from insurers in part to get access to a stable pool of funds for their investment-management operations.

Frank Switzer, a spokesman for Toronto-based Sun Life, declined to comment, as did Mary Claire Delaney of Morgan Stanley, Torie von Alt at Guggenheim and Alex Child-Villiers, a spokesman for Cowdery.

Unlike traditional life insurance, which offers protection against early death, annuities can help savers with long life spans.