MetLife Inc. says it earned less during the third quarter than it originally had hoped but still expects to report more than $600 million in operating earnings for the quarter on $8.6 billion in revenue.

Operating earnings were lower than they were in the third quarter of 2007, but revenue was up about 16%, according to MetLife Inc., New York.

Variable investment income was about $117 million lower than anticipated, but the strength of the dollar and the increase in credit default swap spreads helped the company generate about $735 million in derivative gains, the company says.

MetLife spent about $48 million on severance and other costs related to the company’s “Operational Excellence” initiative.

“MetLife’s Operational Excellence plans are anticipated to extend through 2010,” the company says.

The company will be recognizing about $400 million to $475 million in net investment gains in its third-quarter earnings report on about $324 billion in general account assets.

Unrealized losses on fixed-maturity securities have increased to $17 billion, from $10 billion June 30, while gross unrealized gains have fallen to $5 billion, from $6 billion.

The company has about $4 billion in excess capital, and it believes it has the liquidity it needs to back its securities lending operations, the company says.

“Should MetLife’s liquidity needs under the company’s securities lending program accelerate, MetLife has a pool of $9 billion in cash at the end of the third quarter dedicated to meet those needs and, in addition, the company has the liquidity resources of most of MetLife’s general account assets to draw on,” the company says.

Excluding the unrealized investment losses, MetLife had a book value per share of about $46 per diluted common share Sept. 30 Including the unrealized investment losses, book value was $36, the company says.

MetLife notes that it will be reporting a $460 million net loss related to the split-off of Reinsurance Group of America Inc., Chesterfield, Mo., using Generally Accepted Accounting Principles, but a statutory accounting gain of more than $1 billion for the RGA transaction.

In another announcement, MetLife hinted that it may be looking for acquisitions.

The company says it plans to sell 75 million shares of common stock to the public.

“The offering will supplement the company’s strong capital position and will be used for both general corporate purposes and potential strategic initiatives,” the company says.