Keurig coffee machine maker Green Mountain Coffee Roasters , missed Wall Street's quarterly revenue estimates, knocking 30 percent off the value of its stock at a time when an influential short seller is questioning the company's business practices.

Shares of Green Mountain, the largest U.S. single-cup coffee company, fell 30 percent to $46.75 after the bell.

The stock has fallen 27 percent since October 17 when Greenlight Capital's David Einhorn said he turned negative on the company and cast doubt on Green Mountain's accounting practices and long-term earnings potential.

Green Mountain saw the third-largest net increase in short positions on Nasdaq in the second half of October, with short interest rising to 24.7 million shares on October 31 from 17.1 million on October 14. That rise indicates that more people think that the company's stock price and business will weaken.

However, Green Mountain forecast a profit for the holiday quarter that was largely above analyst estimates.

The company reported fourth-quarter sales of $711.9 million. Analysts were looking for sales of $760.5 million, according to Thomson Reuters I/B/E/S.

Net income was $75.4 million, or 47 cents a share, compared with $27 million, or 20 cents a share, a year earlier. Adjusted profit was 47 cents a share, compared with the 48 cents that analysts were expecting on average.

The Waterbury, Vermont-based company missed sales estimates for the first time in more than eight quarters, and failed to beat profit expectations after five quarters.

(Reporting by Mihir Dalal in New York. Editing by Robert MacMillan and Matthew Lewis)

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