The movie, tentatively titled "The Jayson Blair Project," is expected to be shown on the pay cable outlet next year or early 2005.
Blair resigned as a reporter on May 1 after filing some three dozen phony or plagiarized stories. The scandal eventually led to the resignation of the paper's top editor, Howell Raines.
"Although (Blair) is a real person and there's a tragic aspect to this, there's something snarky and odd that is quite comic about the way he operated," Jon Maas, who's writing the movie, said Wednesday.
Maas said he sees his movie as something similar to "Confessions of a Dangerous Mind," the film based on the autobiography of game show producer Chuck Barris.
"The Jayson Blair Project" is being based partly on articles by former Newsweek writer Seth Mnookin, Showtime said. Maas would not say whether anyone involved in the scandal would cooperate with him in making the film.
Blair has signed to write a book about the incident, titled "Burning Down My Master's House: My Life at The New York Times."
"I am not paying Jayson Blair one penny," Maas said. "I'm not interested in buying the rights to his book. He will not profit financially from this film."
No one has been cast in the title role.
A spokeswoman for The New York Times said the newspaper had no involvement with the film and would not comment on it.
Maas was the writer-producer of an earlier Showtime film, "The Last Debate," about the power of the media and journalistic ethics. He said he's not concerned about taking on a journalism institution.
"I don't think the Times should look at this as an `attack New York Times movie,"' he said. "It's a great newspaper."