Power Financial Corp. swung to a loss for the fourth quarter as the weakening economy led to charges at the firm’s operating subsidiaries.

The net loss for the fourth quarter ended Dec. 31, 2008, was $773 million, or $1.12 per share, compared with net earnings of $532 million, or 73¢ a share, for the same period in 2007, the company said Wednesday.

The company took a charge of $1.207 billion, or $1.71 per share, compared with $32 million in the same period in 2007.

Operating earnings for the quarter were $434 million or 59¢ a share, compared with $500 million, or 68¢ per share in the same period in 2007.

Revenues for the quarter were $7.14 billion, down from $9.43 billion in the prior year quarter.

Power Financial controls Great-West Lifeco, Canada’s second-largest life insurance company, and IGM Financial, the country’s largest nonbank mutual fund manager. Both reported lower profits last month.

Power Financial said the writedowns included $1.35 billion taken by its Great-West Lifeco Inc. unit for Putnam Investments. Boston-based Putnam said Feb. 11 it plans to cut about 260 jobs, representing 11% of its workforce.