Actors John Goodman (L) and Billy Crystal pose for a portrait while promoting the animated film "Monsters University" in Beverly Hills, California May 18, 2013.[Photo/Agencies]

Animated prequel "Monsters University" took home its second US and Canadian box office title with $46.2 million in ticket sales over the weekend, fending off a red-hot debut from Sandra Bullock and Melissa McCarthy in female buddy comedy "The Heat".

Outpacing industry projections, "The Heat" nabbed $40 million from Friday through Sunday and finished in second place, according to studio estimates. Big-budget, explosion-filled "White House Down" fell short of expectations with $25.7 million in its first three days, finishing the weekend in fourth place.

Hollywood forecasters had predicted each of the new films would haul in at least $30 million over the weekend.

Zombie thriller "World War Z", starring Brad Pitt as an ex-U.N. crisis specialist fighting the undead, slipped just one notch to third in its second week in release, earning $29.8 million over the weekend domestically. That brought its global total to $259 million.

Family crowds kept "Monsters University" at the top of the charts following a big debut a week earlier, when it became 14th consecutive film from Walt Disney Co's Pixar unit to open at No 1 on North American (US and Canadian) charts. Combined with global sales, the movie's tally through Sunday crossed the $300 million mark, Disney said.

The prequel to 2001 blockbuster "Monsters Inc." features the voices of Billy Crystal and John Goodman as monsters who flunk out of the college's scare program.

Adult comedy "The Heat" offered an alternative to the summer's family fare and male-oriented action flicks. The film stars Bullock as an uptight FBI agent who is paired with a loud and aggressive cop, played by McCarthy, on a mission to bring down a drug lord. The movie was produced for a modest sum in the low-$40 millions.

Chris Aronson, president of domestic distribution for 20th Century Fox, which released the film, credited "a very, very effective marketing campaign aimed almost exclusively at women" for the film's impressive box office haul.

"When we moved this to summer, we felt we could stand out being a female-event movie," Aronson said, also crediting the "likeable star pairing" of Bullock and McCarthy.

"White House Down" stars Channing Tatum as an aspiring Secret Service agent who finds himself protecting the president, played by Jamie Foxx, as Washington comes under attack.

The White House, US Capitol and Air Force One wind up in flames in the $150 million production from "Independence Day" director Roland Emmerich. The film's plot was similar to the storyline of March release "Olympus Has Fallen".

Sony Pictures, the Sony Corp unit that released the film, said the $25.7 million take was short of expectations but it was confident that strong exit polls and word of mouth from people who had seen it would fuel the box office going into the lucrative July 4 holiday weekend.

"Audiences really love this movie," said Rory Bruer, Sony Pictures' president of worldwide distribution.

In the No 5 spot, Superman reboot "Man of Steel" took in $20.8 million domestically during its third weekend, bringing its domestic total to nearly $250 million and its global take to above $520 million, Warner Bros said.

Sony Corp's movie studio released "White House Down". "The Heat" was distributed by the 20th Century Fox studio, a unit of 21st Century Fox, part of the company formerly known as News Corp.

Paramount Pictures, a unit of Viacom Inc, distributed "World War Z". "Man of Steel" was released by Warner Bros., a unit of Time Warner Inc.

'Tiny Times' premieres in Beijing

Journey to the West: Conquering the Demons