Sony has said a deal to take over film and TV studio Metro Goldwyn Mayer may be facing some "complications".
One of MGM's best loved films is the Wizard of Oz
Talks began in April on a possible deal worth up to $5bn (£2.8bn).
However Sony chief executive Nobuyuki Idei told Reuters news agency: "There are some complications... It's up to the MGM management now."
Earlier this month it was reported that
Time Warner, the world's biggest media group, had also stepped into the MGM fray with a bid of around $4.7bn.
Sony is in discussions to buy MGM for around $5 billion
with partners, Texas Pacific Group and Providence Equity Partners.
However the two sides have been unable to come to a final agreement.
A deal would give the victor access to MGM's film library, a key cash source as more movies are released on DVD.
Any deal with Time Warner would see MGM's pre- and post-1948 movies reunited as Ted Turner's Turner Broadcasting - owned by the media giant - bought up the rights to MGM's pre-1948 films.
The MGM studio was founded in 1924 after a merger between Metro Pictures Corporation, Goldwyn Pictures, and Louis B Mayer Productions.
Classic MGM films include Gone With The Wind, Ben Hur, The Wizard Of Oz, Doctor Zhivago, How The West Was Won and Mutiny On The Bounty as well as many musicals.
The company's large movie library also includes the rights to James Bond films.