NEW YORK (Bloomberg) — MetLife Inc., the biggest US life insurer, was downgraded by Standard & Poor's as the rating firm cut 10 companies in the industry on concern that losses on bonds and mortgage holdings will rise.

"The pressures within the life sector have been building," S&P said in a statement. "Given the disarray in the credit and capital markets, most insurers' financial flexibility has decreased in the past six months."

Life insurers have reduced dividends, cut jobs and applied to the government for aid as the recession pushes down the value of corporate debt and mortgage-backed securities backing policies. New York-based MetLife has reported six consecutive profit declines, while No. 2 Prudential Financial Inc. and Hartford Financial Services Group Inc. both reported losses of more than $1 billion in the second half.

Prudential, Connecticut-based Hartford, Lincoln National Corp., Genworth Financial Inc. and Protective Life Corp. were among the companies cut by S&P.