The last of the major pharmaceutical companies to report on its first quarter, Sanofi-Aventis (NYSE:SNY) proved to be worth the wait. Although accounting gymnastics related to the merger with Aventis make year-over-year comparisons sticky, it seems readily apparent that business was pretty good.

On a comparable basis, sales rose 11.9% to about $8.3 billion, with sales of the company's top 15 products seeing nearly 19% growth over last year. Better efficiencies and cost control led to a nearly 4% improvement in operating margin. Operating income also grew about 22% for the quarter.

Looking at drug-by-drug performance for the top 15 compounds revealed no major negative surprises. Top dog Lovenox posted high-teens growth, while Plavix and Allegra both managed greater than 20% revenue improvement. Lantus, one of the company's insulin products, was exceptionally strong and posted over 55% growth. Lantus continues to prove very successful in the diabetes field, now holding over one-fourth of the U.S. market.

While Sanofi-Aventis did well for itself in the first quarter, the company should have even more in store for the years ahead. Acomplia is the real deal; this weight-loss drug should offer a solid boost to the financials. The company also has promising new drugs for cardiology and cancer, and although I'm not sure they will hit the "blockbuster" mark ($1 billion or more in sales), I don't think they'll exactly be slouches, either.

Given that I own shares of Sanofi-Aventis, it's not going to come as any big surprise that I like the company and the shares. And just a quick note for you conspiracy knuckleheads out there -- I like the shares because I like the company, and not the other way around. Don't waste my time, or yours, with inane "You're just trying to pump the stock" e-mails, OK?

Although I'm not exactly ecstatic about Sanofi's low dividend yield, the company is growing operating income faster than all other major pharmaceutical companies except Wyeth (NYSE:WYE) and Schering-Plough (NYSE:SGP) -- and those companies have the dubious "advantage" of easier comparisons. What's more, with such a strong pipeline, I'm content to see management plow more money into development and product support than dividend payments.

While solid year-to-date performance has pushed up these shares, I certainly think there's more potential ahead. Not only does Sanofi-Aventis have some very interesting drugs approaching the market, but the company is growing solidly in the present as well. Though the stock is not the greatest idea for highly income-oriented investors, I do believe that the growth-at-a-reasonable-price crowd might want to investigate further.

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Fool contributor Stephen Simpson owns shares of Sanofi-Aventis. The Fool has a disclosure policy.