Move Is Official, Letterman Says : Television: Lorne Michaels will develop a replacement show for NBC, which reiterates its commitment to Jay Leno.

The late-night television riddle was formally resolved Thursday, as David Letterman confirmed that he’s taking his caustic comedy act to CBS in August, and NBC announced that it remains firmly committed to beleaguered “Tonight Show” host Jay Leno.

In back-to-back news conferences on the East and West coasts that were longer on humor than hard information, NBC said “Saturday Night Live” producer Lorne Michaels will develop a show to air in Letterman’s 12:30 a.m. slot. The show’s premise is still being developed.

Letterman, appearing in New York with CBS Chairman Laurence A. Tisch and CBS Broadcast Group President Howard Stringer, said band leader Paul Shaffer will follow him to CBS, but could not say whether the show will remain in New York or move to L.A. Asked if he plans to change his brand of acerbic humor, Letterman said, “The show is the show, at 12:30 or 11:30.”

CBS executives declined to discuss the terms of Letterman’s deal, but he is expected to earn about $14 million a year. That compares to Leno’s annual salary of $3 million.

Letterman plans to remain on NBC until his contract expires June 25. The “Late Night” name is owned by NBC. While there’s no title yet for the new show, Letterman alluded to the intense media coverage of the Amy Fisher story, saying, “We’re trying to work in the name Buttafuoco.” Letterman also recounted his Top 10 list of the reasons he’s going to CBS.

They included: “In order to grow as an artist, I feel it’s important to do the same crap over at CBS. . . . Makes sense since I’m already commuting with Andy Rooney . . . Can’t convince (NBC) to do another (Olympic) Triplecast. . . . At last minute, CBS kicked in a new set of Michelins.”

Stringer called it a “Red Letterman” day, and said the comedian will help boost CBS to No. 1 in the late-night ratings, where it has traditionally been weak.

At an earlier news conference in Santa Monica, NBC Entertainment President Warren Littlefield, sitting with Leno, said negotiations with Letterman dragged on for more than a year because management was trying to keep both hosts at NBC.

“In the end, the one thing that David was interested in was the 11:30 time slot,” Littlefield said. “And quite frankly, we have a terrific host at 11:30 in Jay Leno.”

Littlefield refused to disclose his final offer to Letterman or to say when it was made. He acknowledged that NBC had tried to keep Letterman with other incentives, but he said the 11:30 time slot was the key factor.

Both men characterized the situation as tense, and Leno appeared a bit stung by what he called NBC’s foot-dragging. “Welcome to NBC: Never believe your contract,” said Leno, who drove into the news conference on a motorcycle.

When asked if he felt hurt by the ongoing controversy, Leno said he did not feel that he was lied to or deceived. “Everyone was honorable. A little indecisive,” he added, grinning as he let the comment hang.

Letterman and Leno both downplayed the coming competition. Letterman’s break with NBC comes nearly 11 years after “Late Night With David Letterman” premiered on the network on Feb. 1, 1982.

Letterman’s audience in the hour after “The Tonight Show” was relatively small by television standards--he has been averaging 2.5 million households a night this season, compared to 4.4 million for Leno’s show. (In prime time, “Roseanne” averages 19.8 million households per week.)

But his silly stunts, Top 10 lists, Stupid Pet Tricks and irreverence toward his own medium--not to mention his employers--were the type of things the news media picked up on and viewers quoted the next day to friends. He also attracted a young, hip audience for which advertisers were willing to pay a premium.

The show won four Emmy Awards for writing and one for directing, and in 1992 won a prestigious George Foster Peabody Award for “infusing one of television’s oldest and most conventional forms, the talk show, with inventiveness, freshness and vitality.”

Trouble erupted when Johnny Carson announced that he was stepping down after nearly 30 years at the helm of “The Tonight Show,” an NBC institution that earned millions of dollars in profit each year. The network passed over Letterman as Carson’s successor and chose Leno, a frequent guest of Letterman’s in the early years of “Late Night” who had gone on to become permanent substitute host on “The Tonight Show.”

Letterman was irked at the way NBC handled the situation, stories began surfacing about how much money other networks and syndicators would be willing to pay for his services, and the breach widened from there, leading to Letterman’s declaration that he wanted NBC’s 11:30 time slot or would move to CBS to become a competitor.

Greg Braxton reported from Los Angeles and Jane Hall reported from New York.