By ELVA RAMIREZ and PETE DONOHUE

Vodka ads featuring a woman's bottom in a bikini have been stripped from city buses - a cheeky move, according to the liquor's manufacturer.

Viacom, which runs the Metropolitan Transportation Authority's bus billboard program, took the scantily clad posteriors off 100 buses about a month ago.

The back-of-the-vehicle Georgi Vodka ads - known in the marketing trade as bus tails - sparked complaints from around the city, Viacom spokeswoman Jodi Senese said. "We are very aware that bus ads are intrusive," she said. "Buses go through residential areas, by schools and playgrounds."

The ads were purchased by the vodka's manufacturer, Star Industries, whose president, Martin Silver, was bummed by the turn of events.

Silver said he didn't get the expected bang for the buck, even though Viacom replaced the ads with a tamer version. The company may file a lawsuit in defense of its First Amendment rights, Silver said. The MTA was not aware the ads got canned by Viacom, an authority spokesman said.