The Walt Disney Co. and the union representing about 550 feature film animators and writers will launch contract negotiations this week on a successor deal to the current master contract.

The current three-year contract has been extended from its Oct. 31 expiration at Disney’s request. The talks are scheduled to take place on Wednesday and Thursday, then recess to Jan. 25.

The Disney animators are represented by the Animation Guild, which operates as Local 839 of the International Alliance of Theatrical Stage Employees. The contract, also known as the Secret Lab contract, dates back to 1999.

The Animation Guild contract covered work performed on “Frozen,” “Big Hero 6,” “Wreck-It Ralph” and the upcoming “Zootopia,” which opens in March. But it does not cover films shot by Disney’s Pixar division, which was acquired by Disney in 2006 for $7 billion and remains a non-union operation.

In August, members of the Animation Guild ratified a three-year successor deal to its master contract with producers at several of the other studios, including Warner Bros. Animation, DreamWorks Animation and Sony Pictures Animation. That agreement, which covers about 3,000 animators and writers, includes 3% annual wage increases to contract minimums, a 10% pension increase and 30% increases for contribution hours.

The Writers Guild of America West covers TV animation at Fox, including “The Simpsons” and “Family Guy.”