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What: Shares of Express Scripts (Nasdaq: ESRX) have popped today by as much as 15% after the company reported third-quarter earnings ahead of analysts' expectations.

So what: The pharmacy benefits manager reported third-quarter revenue of $11.6 billion, which translated into adjusted earnings per share of $0.79. Analysts were calling for $11.3 billion in revenue and $0.77 in earnings per share.

Now what: The company has been trying to merge with MedcoHealth Solutions (NYSE: MHS) recently in a $29.1 billion deal, and the CEOs of both companies have expressed confidence that the acquisition will pass regulatory muster. Express Scripts has also been locked in a contract dispute with drugstore company Walgreen (NYSE: WAG), which has been weighing on shares. Analysts largely think the dispute with Walgreen won't see a resolution until next year.

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Fool contributor Evan Niu holds no position in any company mentioned. Click here to see his holdings and a short bio. Motley Fool newsletter services have recommended buying shares of Medco Health Solutions. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.