Gilead ( GILD) exceeded analysts' third-quarter top- and bottom-line expectations as sales of its HIV-fighting drugs surpassed estimates, and the company announced an accelerated $750 million share-buyback plan. The stock closed up $3.11, or 8.1%, at $41.39 on Thursday in anticipation of the third-quarter earnings. After the numbers were disclosed, Gilead added another 3.3%. The company said it earned $504 million, or 52 cents a share, in the quarter, compared with $398.3 million, or 42 cents a share, in the year-ago period. Factoring out certain items, the company reported a profit of 55 cents a share, up from 45 cents a share a year earlier. Revenue rose 30% to $1.37 billion. Results topped the consensus estimate of 49 cents a share on revenue of roughly $1.32 billion, according to Thomson Reuters. Total U.S. antiviral sales totaled $712.6 million for the recent quarter, up from $546 million a year prior. The recent quarter includes U.S. sales of $262 million from Truvada and $346 million from Atripla, both of which beat consensus targets of $244 million and $335 million, respectively. Worldwide, Gilead garnered $427.6 million from Atripla and $549.1 from Truvada, along with roughly $155.9 million for Viread. Analyts had expected that negative data on GlaxoSmithKline's ( GSK) Abacavir could be aiding the European launch of Atripla. The company reported worldwide revenue of $91.2 million from Hepsera, $72.9 million from Ambisome and $31.7 million for Letairis. Those results were in line to slightly above analysts' targets.