Letterman apologises to wife on show

The CBS network late-night host, building on Thursday's startling confessional, vowed to repair his relationship with his wife, Regina Lasko, whom he married in March after a years-long courtship.

"Let me tell you folks, I got my work cut out for me," he said ruefully.

Ratings victory

As Letterman faced Monday's show, and the shows that will come after, it was clear that how he deals with his messy situation could prove to be a defining chapter in his long television career.

And, ironically, it could clinch his recent ratings victory in late-night TV.

His dilemma was Topic A on the show as he mixed wisecracks with contrition in a virtuoso balancing act. Noting the cool autumn weather, he reported, "It's chilly outside my house; chilly inside my house."

Then he cautioned the audience, "This is only phase one of the scandal. Phase two: Next week I go on Oprah and sob."

A bit later, guest Steve Martin gave Letterman his kidding consolation: "It proves that you're a human being. And we weren't really that sure before."

Martin Short, making an unannounced appearance, playfully plopped himself in Martin's lap.

"You spend one more minute on his lap, you're gonna get blackmailed," Letterman quipped.

Blackmail threat

Monday's show was the first Letterman had taped since last Thursday, when he disclosed that he had had sexual relationships with women who worked for him and said that he had been the victim of a $US2 million blackmail threat.

During the hour, he also apologised to his staff, which, he said, had been subjected to "being browbeaten and humiliated" by reporters since his revelations.

"My thanks to the staff for, once again, putting up with something stupid I've gotten myself involved in," he said.

Letterman, 62, began dating Lasko in 1986, and they have a son, Harry, who was born in November 2003.

All the affairs took place before Letterman's marriage, said Tom Keaney, spokesman for Letterman's production company, Worldwide Pants.

Letterman arrived on stage on Monday to applause and cheers from his studio audience. After drinking it in, he grinned sheepishly and inquired, with a mock stammer, "Did your, did your weekend just fly by?"

He later joked, "I got into the car this morning, and the navigation lady wasn't speaking to me. Ouch."

In a more sombre display, Letterman voiced his mea culpas.

Details of affairs sketchy

Regarding his wife, he said that, "if you hurt a person and it's your responsibility, you try to fix it."

Letterman has offered no specifics about how many women he had sex with.

But the CBS producer accused of blackmailing Letterman used pages from a former assistant's diary that described an affair with the Late Show host, a law enforcement official said Monday.

The ex-assistant, Stephanie Birkitt, went to live with CBS News producer Robert Halderman, who found her diary describing her relationship with Letterman and used it to help blackmail him, the law enforcement official said on Monday on the condition of anonymity.

Halderman, a producer for the true-crime TV show 48 Hours Mystery, pleaded not guilty last week to extortion charges.