A crowd gathers in Times Square to watch celebrities arrive during the premiere of "Transformers: Dark of The Moon" in New York June 28, 2011.[Photo/Agencies]

LOS ANGELES -- Big-budget action film "Transformers: Dark of the Moon" won the battle of the box office for the second-straight weekend, generating $140 million in global ticket sales and pushing its worldwide total since its debut to $645 million, studio estimates showed on Sunday.

The third installment of the popular "Transformers" films about shape-shifting aliens was the No. 1 film in the United States and Canada with $47 million in sales. It easily beat two new comedies, "Horrible Bosses" which took in $28 million, and family film "Zookeeper," the weekend's No. 3 movie with $21 million.

"Transformers" remained strong over the weekend internationally with $93 million in ticket sales from 59 markets, according to distributor Paramount Pictures.

Overall, the effects-filled Hollywood flick has now taken in $261 million in domestic theaters (the US and Canada) to become the year's highest-grossing movie, so far. And it has hauled in another $384 million overseas.

The success of the 3-D sci-fi flick also helped pull audiences into theaters for the new comedies, which generated decent sales amid low expectations during a summer weekend light on big new releases.

"'Transformers 3' is helping the overall marketplace by performing well," said Paul Dergarabedian, box office analyst with Hollywood.com. The 52 percent drop in domestic ticket sales versus the film's opening weekend last week was unusually low after a big opening, he said.

BAD IS GOOD

"Horrible Bosses," which centers on three male friends who plot to kill their mean bosses, did better than expected as adult comedies like it and "Hangover 2" and "Bad Teacher" continued to appeal to fans this summer. "Bosses" stars Jason Bateman, Charlie Day and Jason Sudeikis, along with Jennifer Aniston as one of the bosses.

"Zookeeper," a family-oriented comedy starring Kevin James, also turned in a solid start domestically and good numbers overseas, distributor Sony Pictures Entertainment said. International sales hit $7.5 million, mostly from Germany and Mexico, on about 1,500 screens.

"Cars 2," the sequel from Disney's Pixar animation studio, claimed the No. 4 spot on domestic box office charts with $15 million, and the Cameron Diaz comedy "Bad Teacher" was fifth with $9 million.

"Transformers" was released by Paramount Pictures, a unit of Viacom Inc, "Horrible Bosses" was distributed by Warner Bros., a division of Time Warner Inc, and "Zookeeper" and "Bad Teacher" were released by the studio division of Sony Pictures Entertainment, a unit of Sony Corp. Walt Disney Co is the parent of Pixar.