HARTFORD, Conn.—Hartford Financial Services Group Inc. is in talks to sell most of its life insurance unit to Canada's Sun Life Financial Inc., Bloomberg News reported Wednesday, citing three people familiar with the situation.

Bloomberg also reported that Hartford had been in separate talks with MetLife Inc., which ended last month.

A spokeswoman from the Hartford said the company would not comment on market speculation.

The report that the Hartford, Conn.-based company is considering splitting its life insurance operations from its property/casualty business came one day after Standard & Poor's Corp. cut Hartford's credit rating to BBB from BBB+, which was the second time S&P had downgraded the company in a week.

Hartford, which has been hit hard by investment losses at the life insurance operations, posted a $2.75 billion net loss in 2008.

In a statement Tuesday, S&P analyst Shellie Stoddard said that Hartford's "earnings, capitalization, and financial flexibility have been weakened" by the equity market's decline. She added that the "uncertainty of this financial stress could erode Hartford's brand and diverse competitive advantages."