MetLife Inc. (MET) swung to a second-quarter loss as the company recorded $3.83 billion in pretax investment losses stemming from losses in derivatives and other asset classes, and from improvements in MetLife's credit spread.

MetLife, the largest U.S. life insurer and a bastion of balance-sheet strength, declined to seek a handout from the government earlier this year, having raised capital on its own to weather the last year's financial storm. The company has also streamlined its structure, a move analysts at Fox-Pitt Kelton said could boost revenue and trim $600 million from annual expenses.

Given the company's relative strength, many on Wall Street think MetLife could be on the prowl for acquisitions, though recent talks to buy American International Group Inc.'s (AIG) international life-insurance operations appear to have stalled.

The company reported a loss of $1.43 billion, or $1.74 a share, compared with year-earlier earnings of $915 million, or $1.22 a share. Operating earnings, which exclude net realized capital gains and losses, fell to 88 cents a share from $1.22.

Revenue slid 31% to $8.27 billion, which was hurt by the $3.83 billion of investment losses.

Analysts projected per-share operating earnings of 68 cents on revenue of $11.71 billion, according to a poll by Thomson Reuters.

The company reported an 8% premium increase in the institutional segment but a 3% decline for the individual business. U.S. annuity deposits rose 43%.

Among competitors that have reported results so far, MetLife blew away the competition in the amount that customers deposited in variable annuity accounts, with $2.8 billion in net inflows during the quarter.

Hartford Financial Services Group (HIG) reported a second-quarter net outflow of $1.6 billion in its retail variable annuity business, while Lincoln National Corp. (LNC) reported a net inflow of $1 billion.

David Havens of Hexagon Securities LLC said via email that MetLife's increase in variable annuity deposits was "much better than most other life insurers we've seen so far" and is a sign that "Met was viewed as a 'safe haven' by the market."

Earnings in MetLife's institutional business - which includes group life, retirement and savings products - fell 32%. The individual business, which includes life insurance and annuities marketed through agents, had a 14% increase.

MetLife's stock has essentially tripled in the past five months but remains down almost half from last September's 52-week high. Shares of MetLife were down $1.7% to $33 in post-market trading, after closing up 4% on a surge among life insurers generally on Thursday.

-By Lavonne Kuykendall and Jay Miller, Dow Jones Newswires; (312) 750-4141; lavonne.kuykendall@dowjones.com