NBC has canceled a deal with MGM studios for a series of commercials promoting its forthcoming movie "Dirty Work," on the order of Don Ohlmeyer, president of NBC's West Coast division, because the film stars Norm Macdonald, the one-time anchor of the "Weekend Update" segment of "Saturday Night Live."

Ohlmeyer forced Macdonald off that assignment this season, citing declining ratings and what he said was a drop-off in quality.That touched off a nasty feud that had Macdonald appearing on David Letterman's late-night show on CBS (and he's another former NBC star with a feud going with Ohlmeyer) and Howard Stern's radio show. Macdonald berated Ohlmeyer for dismissing him, saying that Ohlmeyer objected to his often vicious barbs about O.J. Simpson during his "Update" segment.

Ohlmeyer, a friend of Simpson's who stood by him during his trial and acquittal, has said that had nothing to do with the decision to remove Macdonald. He pointed to the innumerable monologue jokes that NBC's biggest late-night star, Jay Leno, has delivered about Simpson, without drawing any reaction from Ohlmeyer.

"If he had just come after me, this would not have happened," Ohlmeyer said in a telephone interview on Tuesday. "But he started going after `Saturday Night Live' and NBC, and that just wasn't acceptable."

The decision to cancel the commercials was Ohlmeyer's, a senior executive said.

Gerry Rich, president of worldwide marketing for MGM, said, "We were certainly surprised by NBC's decision." MGM had a contract with NBC going back to last spring for commercial time to promote its movies, Rich said in a telephone interview. The studio had also bought individual ads for "Dirty Work" on other NBC shows, Rich said.

The studio was informed on May 26 that its first commercial for the film did not run in the previous Saturday's edition of "Saturday Night Live." It was then, Rich said, that NBC informed MGM that no commercials for Macdonald's movie would appear on the network.

"It put us in a difficult situation, having to change our media plan at the 11th hour," Rich said. He did not specify how much money MGM had committed, though he said it "wasn't pennies." He added that NBC's audience was considered especially good for movie studios to reach. But he added: "We had options. We moved the commercials to Fox and MTV and other places. They were happy to take our money."

The timing of the cancellation, which was first reported by Daily Variety Tuesday, means that NBC will probably lose some revenue. In June, with the television season over and repeats on most of the time, the television commercial marketplace is soft. Many networks are looking for advertisers to buy time.

Rich pointed out that the film's theme carried a certain added resonance because of Ohlmeyer's decision. "In the movie, Norm plays a guy who creates a revenge-for-hire business. This whole thing is absolutely a revenge move."