(Adds domestic ad revenue, comment from Gabelli and Snapchat deal)

By Jessica Toonkel and Anya George Tharakan

Feb 9 (Reuters) - Viacom Inc VIAB.O , the owner of MTV, Comedy Central, Nickelodeon and movie studio Paramount, reported a steeper-than-expected drop in quarterly revenue, hurt by lower advertising sales in the United States and few hit movie releases in the period.

Domestic advertising revenue fell 4 percent, as price increases were more than offset by a decline in traditional ratings at some of Viacom's networks. Three analysts told Reuters they had forecast domestic ad revenue to fall 5 percent in the quarter ended Dec. 31. Still, the drop was an improvement from the September quarter's 7 percent fall.

Viacom has struggled with lower ratings for its cable networks in recent years as younger viewers migrate to online and mobile video.

The company's board last week named Chief Executive Philippe Dauman as executive chairman, replacing 92-year-old majority owner Sumner Redstone and piling pressure on Dauman to improve Viacom's performance.

Last week, Mario Gabelli, the second-largest owner of voting shares in Viacom after the Redstone family, said that Dauman has six to nine months to turn the company around.

"Philippe has to deliver," Gabelli told Reuters last week, adding that he wants to see a more aggressive digital and mobile strategy from Viacom.

The company on Tuesday announced a deal with video messaging app provider Snapchat that gave Viacom exclusive rights to sell advertising around Snapchat's content.

Revenue in Viacom's filmed entertainment division, which includes Paramount, fell 15 percent to $612 million, hurt by fewer big film releases. The year-earlier quarter included the strong performance of "Teenage Mutant Ninja Turtles".

Net income attributable to Viacom fell to $449 million, or $1.13 per share, in the fiscal first quarter from $500 million, or $1.20 per share, a year earlier.

Total revenue declined 5.7 percent to $3.15 billion.

Excluding items, Viacom earned $1.18 per share.

Analysts on average had expected a profit of $1.18 per share and revenue of $3.26 billion, according to Thomson Reuters I/B/E/S.

(Reporting by Anya George Tharakan in Bengaluru and Jessica Toonkel in New York; Editing by Ted Kerr and Tiffany Wu) ((anyageorge.tharakan@thomsonreuters.com; within U.S. +1-646-223-8780; outside U.S. +91 80 6749 7118;; Reuters Messaging: Reuters Messaging: anyageorge.tharakan.thomsonreuters.com@reuters.net))

Keywords: VIACOM RESULTS/