The biggest flop of the summer so far came from perhaps the unlikeliest source: Will Smith, one of Hollywood's few remaining global superstars.

'After Earth,' a postapocalyptic adventure that Mr. Smith helped write and produce opened to an estimated $27 million in box-office receipts in the U.S. and Canada. Mr. Smith co-stars in the picture with his son Jaden,

The film came in third place, behind 'Fast and Furious 6,' which took No. 1 for the second weekend in a row, and the new magic-themed thriller 'Now You See Me.'

Sony 6758.TO -3.84% Pictures Entertainment spent nearly $150 million to make 'After Earth,' which was savaged by critics.

'While we were expecting more domestically, we believe the film will perform strongly when we open overseas over the next few weeks,' a Sony spokesman said by email.

Mr. Smith is one of the film industry's few remaining stars whose mere presence in a movie usually guarantees big ticket sales. 'After Earth' is his most significant flop since 2000's 'The Legend of Bagger Vance.'

Because the movie has yet to open in most foreign countries, where Mr. Smith remains quite popular, it remained to be seen how 'After Earth' will fare for Sony Pictures.

But the weak domestic debut came at a bad time for the studio, which has been criticized for overspending by Sony Corp.'s largest shareholder, Daniel Loeb. Mr. Loeb is pushing to spin off 15% to 20% of the company's entertainment assets into a public listing.

'Now You See Me' opened to a solid $28.1 million. It cost a little more than half what 'After Earth' took to make and has an ensemble cast with no A-list stars, meaning few people in Hollywood expected the thriller to be the weekend's biggest new film.

The movie, which features Jesse Eisenberg and Morgan Freeman, earned stronger reviews than 'After Earth' and a A- from opening-night audiences, according to market research firm CinemaScore. Mr. Smith's picture received a B.