SUNNYVALE. Calif. TheStreet) -- Palm ( PALM) shares fell 14.5% in after-hours trading after its third-quarter loss narrowed but the smartphone maker said revenue in the fourth quarter would come in much lower than expected. Palm estimated fourth-quarter revenue of less than $150 million, below the estimate of analysts polled by Thomson Reuters of almost $306 million. A year earlier, Palm reported revenue of $113.2 million. Palm also said it shipped 960,000 smartphones during the third quarter, a 23% increase from the second quarter and an almost 300% increase from a year earlier. But smartphone sell-through, or the number of phones that were bought by consumers, was 408,000 units, down 29% from the second quarter and down 15% from last year. "Our recent underperformance has been very disappointing, but the potential for Palm remains strong," said Jon Rubinstein, Palm chairman and CEO, in a statement. Palm reported a third-quarter adjusted loss of 61 cents a share on sales of $366 million, beating its own guidance for sales in a range of $300 million to $320 million. Analysts had been expecting a third-quarter loss of 42 cents a share. In after-hours trading Thursday, Palm shares fell 82 cents to $4.83. -- Reported by Joseph Woelfel in New York. Follow TheStreet.com on Twitter and become a fan on Facebook.