Weiss Ratings, a Jupiter, Fla.-based independent rating agency of U.S. insurance companies and financial institutions, found that profits at the 20 largest life and annuity insurers in the U.S. decreased by 84 percent in 2011, going from $14.8 billion to $2.4 billion.

Those 20 companies account for 54 percent of the industry's assets, but generated only 12.8 percent of its net income in 2011. Overall the industry earned $18.6 billion last year, down 38.2 percent from $30.1 billion in 2010, reports Weiss Ratings.

In a statement announcing the results, Gavin Magor, senior financial analyst at Weiss Ratings, said that while the declines may seem "dramatic," the drops do not put the companies at risk of failure. "Much of the decline is attributable to the companies paying out more annuity withdrawal benefits and adding to reserves at a time when contract holders are taking increasingly greater advantage of such benefits," he states.