Updated from July 21Driven by strong consumer sales, Symantec ( SYMC) increased first-quarter revenue by 48% year over year and beat Wall Street's profit expectations by 5 cents, the antivirus software maker reported after Wednesday's closing bell. In premaret trading the stock was up 97 cents, or 2.3%, to $44.02 a share. It closed Wednesday off 5 cents to $43.05. Excluding items, the company earned a profit of $142 million, or 39 cents per share, on sales of $577 million in the quarter ended July 2. Analysts polled by Thomson First Call were expecting a pro forma profit of 34 cents a share on sales of $548.95 million. The Cupertino, Calif., company earned $131 million, or 37 cents a share, compared to a profit of $59 million, or 18 cents a share, a year ago, the company said, according to generally accepted accounting principles. Looking forward to results for the October quarter, the company told investors to expect revenue of $580 million, an increase of $15 million over prior guidance. Wall Street was expecting sales of $568.32 million. Symantec also raised earnings guidance for the quarter, saying it expects EPS of 37 cents, a 3-cent increase vs. prior guidance and 2 cents better than analysts had forecast.