Supplemental life and health insurer Aflac (NYSE:AFL) has made quite a name for itself, thanks to its duck mascot. Unfortunately, third-quarter earnings were nothing to quack about. Still, operating results were not too shabby, and the company is projected to continue growing in the double digits.

For the third quarter, revenue was flat at $3.7 billion. This is attributed to a weak yen, which is a significant currency for Aflac, as 74% of last year's revenue stemmed from Japan (the rest came from the U.S.). You can look here for further details of how the yen affects company results, but in a nutshell, the impact to Aflac's operations is more financial than material.

Net earnings fell almost 19%, but this was attributed to higher investment gains and a deferred tax benefit, both of which occurred in last year's quarter. Aflac believes that operating earnings are a better reflection of how its core insurance business is performing. Operating earnings grew 12.1% for the quarter when excluding yen currency impacts.

Nevertheless, the market was unenthused about the quarterly results, as new sales trends were weak in Japan, worrying analysts. Overall profitability and earnings trends are doing fine, though, as net investment income improved and Aflac paid out less in insurance benefits. The U.S. also continues to perform well, but Japanese growth concerns sent the stock down about a buck yesterday, even though earnings met analyst expectations. With the stock at a recent $43.65, it has trended back toward its 52-week lows.

On a more positive note, management announced it will be increasing its dividend 23.1% starting next quarter; then, in the first quarter of 2007, it will increase it an additional 15.6%, for a year-over-year gain of 42.3%. It also expects 2006 operating earnings to grow 15% to $2.92 per share, with a similar gain targeted for 2007.

I'm no insurance guru, but I've noticed that Aflac is one of the more consistent performers in the space, having grown total revenue 8.2% on average over the past five fiscal years, and net income 16.6% over that time frame.

Competitors include Unum Provident (NYSE:UNM), Conseco (NYSE:CNO), Assurant (NYSE:AIZ), and Delphi Financial (NYSE:DFG), while behemoth insurance firms include AIG (NYSE:AIG) and Metlife (NYSE:MET). An investment in Aflac is also a call on how the Japanese supplemental insurance market fares, but few can match its overall growth track record.

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Aflac is a Stock Advisor recommendation.

Fool contributor Ryan Fuhrmann is long shares of Aflac but has no financial interest in any other company mentioned. Feel free to email him with feedback or to further discuss any companies mentioned. The Fool has an ironclad disclosure policy.