Updated from 7:10 a.m. EDTViacom ( VIAB) shares rose 3% Thursday after the company pleasantly surprised analysts with better-than-expected revenue and earnings. First-quarter advertising sales at the media and entertainment conglomerate grew by 21% over year-earlier results. Revenue growth was strongest at two key divisions, with cable networks up 21% and television up 18%. The company reiterated its guidance for full 2004 financial performance. "I'm extraordinarily optimistic about the remainder of '04," Viacom President Mel Karmazin said on a conferent call with analysts Thursday morning. For the first quarter ended March 31, Viacom posted net income of $711 million, or 41 cents per share, up from $443 million, or 25 cents per share, one year earlier. The 2004 number includes the recognition of a tax benefit of $141 million stemming from the resolution of a tax audit covering 1997 through part of 2000; excluding that benefit, Viacom earned $570 million, or 33 cents per share. The Thomson First Call consensus forecast was for 31 cents a share. The New York company reported $6.77 billion in revenue, up 12% from the $6.05 billion reported in the first quarter of 2003 and ahead of the consensus figure of $6.52 billion. Operating income was up 20% to $1.18 billion, better than analysts' expectations of $1.08 billion.