David Letterman was on the receiving end of a sales pitch, not a shakedown, a defense lawyer said Tuesday as he argued that a TV producer accused of extorting the comic was simply peddling a screenplay.

Robert J. "Joe" Halderman's lawyer asked a judge to toss the attempted first-degree grand larceny case, which spurred Letterman to acknowledge his office dalliances in a startling on-air monologue last month. Attorney Gerald Shargel said the $2 million exchange was business, not blackmail.

"This was a commercial transaction. Nothing more," he said.

The first outlines of Halderman's defense spotlighted Letterman's behavior, drawing a sharp response from the "Late Show" host's camp. A lawyer for Letterman said the comic was prepared to testify if the case went to trial.

"It's classic blackmail, no matter how Mr. Halderman's lawyer wants to dress it up," Letterman attorney Daniel J. Horwitz said outside court.

In papers filed Tuesday, Shargel argued that the indictment against Halderman should be dismissed because his conduct wasn't a crime, among other claims. Assistant District Attorney Judy Salwen said she was confident a judge would find the indictment was on solid legal ground.

State Supreme Court Justice Charles Solomon is expected to rule in January.

Halderman acknowledges giving Letterman's driver a package on Sept. 9 that included the supposed screenplay "treatment" _ or synopsis _ and some "source material."

Authorities say the materials included a letter saying Halderman needed to make "a large chunk of money" and a claim that the screenplay would depict how Letterman's world would "collapse around him" when information about his private life was disclosed. Photos, personal correspondence and portions of a diary also were enclosed, authorities said.

The diary entries were allegedly written by Halderman's former girlfriend and outlined her affair with Letterman.

Authorities then taped two conversations between Letterman's lawyer and Halderman _ including an exchange in which the lawyer gave Halderman a phony $2 million check after he demanded it as hush money, the Manhattan district attorney's office said. Halderman was arrested after depositing it.

The day before prosecutors unveiled the case last month, Letterman divulged it on his show, acknowledging he had had sex with women who worked for him.

Shargel's court filing said Halderman simply realized he had "a valuable subject for a book or a movie" and sold it to Letterman, threatening to do nothing more than sell it elsewhere if the TV host rejected it.

"I have no plans to do anything other than either sell you this option _ this screenplay _ to you and therefore you own the story. Or if you don't and you're not interested, as I've said, then that's fine, and I will proceed, and I will do what I want to do, which is what I've been thinking about doing, anyway _ which is writing a book," Halderman told Letterman's lawyer in one of the taped exchanges, according to the filing.

Letterman's lawyer said criminal charges would follow if Halderman released the information himself, the filing said. Halderman, it said, responded: "I don't agree with your position on that."

Some other defendants in extortion cases have argued they were just doing business. In the 1980s, a Maryland union official accused of demanding cash to approve payments to a building contractor maintained the two had a business dispute over construction costs for the union headquarters; the union official eventually pleaded guilty.

Legal experts say the line between extortion and playing hardball can be blurry. Continued...