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What: Shares of ADTRAN (NASDAQ:ADTN) have run higher today by as much as 15% after the company reported first-quarter earnings.

So what: Revenue in the first quarter was $143 million, topping the $139.8 million that the Street was expecting. That top-line beat translated into an even bigger bottom-line beat, with adjusted earnings per share of $0.17 easily besting the $0.08 per share that investors thought was in store.

Now what: CEO Tom Stanton said that the company's domestic carrier business was getting stronger, and international sales helped the company put up a sequential revenue increase. ADTRAN also announced a $0.09 per share quarterly dividend. Jefferies analyst George Notter isn't impressed though, keeping an "underperform" rating and citing intensifying competition that could lead to market share losses.

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