LOS ANGELES — Roger Ebert has turned thumbs down on thumb reviews for “At the Movies with Ebert & Roeper.”

Ebert, who is negotiating a new contract with the syndicated TV show’s distributor, Disney-ABC Domestic Television, is a copyright holder on the signature “thumbs up-thumbs down” judgment that’s part of each film review.

He has “exercised his right to withhold use of the `thumbs’ until a new contract is signed,” the Walt Disney Co.-owned company said in a statement released Friday to The Associated Press.

Health problems have kept Ebert from appearing on the show for more than a year, with guest hosts filling in. In the new season starting this weekend, co-host Richard Roeper will be joined for the first few months by movie critic Robert Wilonsky of the Dallas Observer.

Two episodes have been filmed so far without the catchy thumb assessment, which has become a staple of movie marketing and, in turn, a big part of the show’s influence.

Major releases including “Superbad” and “The Bourne Ultimatum” boast in newspaper ads published Friday of receiving “two big thumbs up” from the show, and at least five other films cite their favorable thumb treatment.

Ebert, 65, holds the copyright to the critique with the estate of Gene Siskel, his original co-host. Ebert, a film critic at the Chicago Sun-Times since 1967, and Siskel, who was at the rival Chicago Tribune, launched the show in 1975. Siskel died in 1999.

A request for comment from Ebert was made Friday through a publicist for the show and by e-mail. He did not immediately respond.

The Pulitzer Prize winner has co-hosted the show with fellow Sun-Times columnist Roeper since 2000. Although he has continued to write reviews and books, his health problems have raised questions about his future on TV.

Ebert underwent a series of cancer surgeries, most recently in June 2006 when he had a growth on his salivary gland and part of his right jaw removed. Two weeks later, he had emergency surgery after a blood vessel burst near the site of the operation.

A tracheostomy, a procedure that opens an airway through an incision in the windpipe, left him unable to speak, a condition he’s said would have to be remedied by further surgery. But he is cancer-free, he told the AP earlier this month.

“We remain hopeful that Roger will return to the show,” the Disney company statement said. “We have kept his `seat in the balcony’ open for the past 14 months and will continue to do so, utilizing guest critics who have appeared with Richard Roeper.”

Ebert wrapped each episode by announcing “the balcony is closed.”