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What: Shares of Lexmark International (LXK) tanked today by as much as 16% after the company reported earnings.

So what: Revenue in the fourth quarter was $967 million with non-GAAP earnings per share of $0.61. While sales came in better than expected, costs were higher than investors anticipated, which led to a disappointing bottom line. Analysts were modeling for $933 million in sales and $0.90 per share in profit.

Now what: Earnings were hurt by higher-than-expected taxes as well as a shift of sales toward higher tax geographies. The company hopes to realize cost savings of $85 million in 2013 from initiatives announced last August. Guidance for the first-quarter calls for revenue to fall 11% to 13%, with non-GAAP earnings per share of $0.80 to $0.90, also worse than expected.

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