MetLife (NYSE:MET) may not be flashy, but the company continues to get the job done. With the acquisition of Citigroup's (NYSE:C) Travelers Life and Annuity business, MetLife is now the U.S.'s largest life insurer. That sort of scale should produce more benefits down the road.

For the recently completed fourth quarter, total revenue rose 16% as premiums and fees rose 13%. That fell slightly below the average expectation, but operating earnings grew 18% in the quarter and slightly exceeded estimates -- suggesting that MetLife may be doing an even better job driving synergies from the acquisition than most observers had expected.

Generally speaking, this was a strong quarter across the board. All but one of the company's major operating segments (variable and universal life) saw operating earnings increase from last year. What's more, each of the five main businesses (institutional business, individual business, auto/home, reinsurance, and international) saw earnings rise at least 26% for the quarter.

It's not all easy sledding, though. Like its peers, MetLife has to deal with the challenge of low interest rates, and competition in businesses like auto insurance is heating up. Though I'd expect stronger firms like MetLife and Allstate (NYSE:ALL) to weather this just fine, it could still make earnings growth a bit more challenging -- and nobody really likes extra challenges, do they?

A better dividend would be nice, but that should come in time. MetLife's international business also has room for improvement, at least compared to others like Prudential (NYSE:PRU). But if MetLife can maintain its high return on equity and continue to leverage its brand both here and abroad, shareholders should enjoy solid performance from this company and this stock in the coming years.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).