UPDATE 2-'Bruno' fashions top spot at U.S. box office

* "Bruno" leads North America, U.K. and Australia

* "Transformers" soars to $339 million in North America

* "Ice Age" top film overseas (Adds big drop for "Bruno," foreign sales for "Ice Age" and "Transformers" in paragraphs 3-6)

LOS ANGELES, July 12 (Reuters) - "Bruno," British satirist Sacha Baron Cohen's latest subversive outing, narrowly claimed the No. 1 spot at the weekend box office in North America, according to studio estimates issued on Sunday.

The "mockumentary," in which Baron Cohen plays a gay Austrian fashion model seeking fame in the United States, sold $30.4 million worth of tickets during the three days beginning July 10, distributor Universal Pictures said.

But the film lost 39 percent of its audience from Friday to Saturday, a hefty drop given that movies usually see an uptick in that period.

Rival studios pounced on the slide, forecasting "Bruno" would have a short run in theaters. But Universal distribution president Nikki Rocco said such a dip "was not unusual in summer."

"Ice Age: Dawn of the Dinosaurs" held steady at No. 2 with $28.5 million, taking the 12-day haul for 20th Century Fox's prehistoric cartoon to $120.6 million. The film was the top draw internationally over the weekend, with $98 million from 102 markets. Its total foreign haul stands at $327 million.

Last weekend's North American champion, "Transformers: Revenge of the Fallen," slipped to No. 3 with $24.2 million. After 19 days, Paramount Pictures' robot sequel has earned $339.2 million in North America, easily the biggest movie of the year. Its international haul rose to $364.5 million.

The one other new entry was Fox's teen romantic comedy "I Love You, Beth Cooper," starring Hayden Panettiere in the title role. It came in at No. 7 with $5 million, in line with the studio's modest expectations.

The opening for "Bruno" was also in line with the forecasts of Universal Pictures, a General Electric Co (GE.N) unit, which paid independent producer Media Rights Capital $42.5 million for distribution rights in North America and eight foreign territories. Media Rights declined to disclose the budget.

Baron Cohen's previous release, the similarly outrageous "Borat," opened with $26.5 million in November 2006. But that was from about 800 theaters, while "Bruno" played in 2,756 theaters. "Borat" ended up with $128.5 million in North America and an additional $133 million internationally.

Universal said "Bruno" earned $20 million from the eight international markets, led by No. 1 bows in Britain ($8.1 million) and Australia ($6.1 million).

"Bruno" faced a similar storm of controversy as "Borat."

In the new film, Baron Cohen's character sashays across the American landscape, piling on the homosexual activity for unsuspecting co-stars and a squeamish audience. Critics mostly liked the movie, while gay-rights groups were mixed in their reactions.

Both films were directed by Larry Charles, a former writer/producer on "Seinfeld."

Exit data provided by Universal indicated that men made up 56 percent of the "Bruno" audience in North America, in line with the turnout for "Borat."

But this time, 54 percent of moviegoers were aged 25 and older, while 53 percent of the "Borat" crowd was aged under 25. Both films were rated "R" in the United States, requiring moviegoers under 17 to be accompanied by an adult.

Universal's Rocco said the film would be "very profitable" for the studio, which picked up the rights before "Borat" was released.

Fox is a unit of News Corp (NWSA.O). Paramount is a unit of Viacom Inc (VIAb.N). (Editing by John O'Callaghan)