Dell Inc reported higher-than-expected quarterly profit and revenue on strong sales of its notebook computers, though its gross margin was slightly below analysts' forecasts.

Shares of the world's No. 3 PC maker fell 2.9 percent in after-hours trading on Thursday.

Dell reported a net profit of $334 million, or 17 cents a share, for its fiscal fourth quarter ended January 29, compared with $351 million, or 18 cents a share, in the year-ago period.

Excluding items, Dell earned 28 cents a share against the average Wall Street forecast of 27 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 11 percent to $14.9 billion, beating the average estimate of $13.8 billion. But adjusted gross margin was 17.4 percent, compared with analysts' average expectation of 18 percent.

Although the company did not provide a formal outlook, it said demand in the commercial business had improved during the fourth quarter and said it was cautiously optimistic that the trend would continue into fiscal-year 2011

Shares of Round Rock, Texas-based Dell closed 1.98 percent higher at $14.43 on Nasdaq, and fell to $13.97 in extended trading following the results.

(Reporting by Gabriel Madway; Editing by Richard Chang)