NBC

Howie Mandel did everything but drop to his knees ... begging Nick Cannon to return as host of "America's Got Talent."

Howie -- 1 of 4 judges on the talent show -- made a passionate plea Sunday at LAX. Howie's pretty damn adamant -- Nick's the heart and soul of the show.

Nick Cannon was "shaken to his core" and seriously questioned his value as an entertainer after NBC unleashed its fury on him, and that led him to the decision to quit "America's Got Talent."

Sources familiar with the situation tell us, Nick was devastated when he learned the network was on the verge of firing him as host of 'AGT.' He looked at the long history of entertainers -- Johnny Carson, Jay Leno, David Letterman and many others -- who trashed their networks right on their shows, and the brass allowed it. Yet Nick went on Showtime, made a few "harmless comments about NBC," and he was threatened with termination.

One example that hit home with Nick was Tracy Morgan, who made a comment during a show and suggested he might knife his son if he found out he was gay. NBC execs defended Morgan.

We're told Nick started to question his own self-worth as an entertainer, thinking he was being treated differently from the others because he just wasn't that good.

He also took into account losing his salary ... we've learned Nick has been pulling in around $4.5 million a season for 'AGT.'

Nick, we're told, was in a terrible state after NBC went on the attack. One source says it was emotionally harder on him than dealing with his very serious medical problems, including Lupus.

Cannon decided in the end he believed in himself and was undervalued by the network ... so he quit.

Nick Cannon just dashed the hopes of NBC and 'AGT' ... because he made it clear there is NO chance he'll come back to the show.

Nick was at LAX Tuesday and showed firm resolve ... he's done with the show. As TMZ reported, Nick said he was leaving 'AGT' after NBC execs seriously discussed firing him for talking smack on the show and NBC on his Showtime comedy special.

"America's Got Talent" execs desperately want to keep Nick Cannon ... but if he really wants to walk, they likely won't hold him to his contract.

Production sources with knowledge of the situation tell us the show fires up next month, but honchos aren't scouting for new hosts ... at least not yet. They're hoping Nick has a change of heart.

If Nick holds firm, NBC likely won't sue him for breach of contract.

Nick Cannon pissed off some NBC execs with a joke he made during a stand-up comedy special -- and it nearly cost him his job on "America's Got Talent" ... TMZ has learned.

While Nick was recording the special more than a month ago, he joked with the audience that NBC was making him lose his "black card" -- strongly insinuating the network wanted him to show less swagger on 'AGT.'

Sources familiar with the situation tell us NBC execs got wind of it when Nick was promoting the special on "The Howard Stern Show" ... and thought he was disparaging the network -- a violation of his contract. We're told his deal has a clause that bars him from talking about the network without approval.

There were serious discussions about axing him for breach of contract, or simply because ... if he's so miserable, why not just let him go?

Ultimately, the execs decided Nick had simply made a passing comment. We're told they like him and didn't want to blow the relationship. He'll be shooting 'AGT' next month.

As for the comedy special, it airs Friday night on Showtime and we're told the "black card" comment is in it.

Matt Lauer says Oprah joining "60 Minutes" on CBS is great ... for CBS.

We got the NBC "Today" host in NYC Tuesday, where we asked if O joining their rival network was good for competition.

When you go to the "Today" show with a shirt suggesting Bill Clinton did what Donald Trump said he did ... you gotta be ready for someone to kick your ass ... so says NBC.

Mark Gallagher went to 30 Rock before the election and wore a t-shirt with Clinton's face and the word "rape."

He claims he was standing there minding his own business when NBC security -- whom he called a "goon squad" -- descended on him and beat the crap out of him. He has sued NBC for $53 mil.

NBC has now fired off its answer, saying when someone does something as incendiary as Gallagher did, they assume the risk someone will come after them. NBC does not get specific, but the network disputes Gallagher's version of the facts ... presumably what he did before the incident.

And this is the best. NBC says Gallagher had a duty to minimize his damages by getting quick medical help, which he did not do. The legal docs say he could have availed himself of the benefits of the Patient Protection and Affordable Care Act -- aka Obamacare.

Lara Spencer and Megyn Kelly may have hugged, kissed or schmoozed before the camera rolled, but it certainly wasn't apparent from what we see at baggage claim at JFK.

The 'GMA' host and the soon-to-be NBC talk show host were feet from each other Monday night, but not a word was spoken ... at least as far as we can see.

ABC and NBC are in fierce competition, but then again competitive anchors still chew the fat.

NBC sent a "goon squad" to manhandle a "Today" show audience member because he's a known Trump supporter and they hated his t-shirt ... according to the guy's new lawsuit.

Mark Gallagher claims NBC security descended on him and roughed him up last month because he was pro-Trump ... according to the docs. He says he was doing nothing wrong at the time -- just chatting 2 ladies and wearing an anti-Clinton shirt.

Gallagher admits he had a motive for being in the "Today" audience ... he believes Bill Clinton is a rapist, and wanted to get some TV time for a shirt with Bill's face and the word "RAPE" on it. He says he was successful doing this the day before on "Good Morning America."

According to the suit ... Gallagher was assaulted by the goons before he even had a chance to take off his sweater and reveal his shirt. He claims he was struck in the back of the head with a security radio and sustained injuries to his neck, lower back, ribs, arms and ankle while being removed ... and has bruises to show for it.

Gallagher is suing NBC Universal for more than $53 million. We reached out to NBC for comment, so far no word back.

Billy Bush and NBC have reached a financial settlement on his "Today" contract ... officially ending his employment with the network after the Donald Trump tape leaked.

Sources with direct knowledge of the negotiations tell us Billy is happy with the final numbers ... which are confidential. As we reported, Bush had just joined NBC's flagship show in August, signing a 3-year deal for $3.5 million per year.

NBC suspended him after the "Access Hollywood" tape came out 10 days ago. Our sources said Bush felt the punishment was unfair because he'd openly talked about the tape in front of his bosses ... and was never disciplined.

We're told he felt like a scapegoat and was cut loose purely for PR reasons.

An NBC memo to staffers said, "While he was a new member of the TODAY team, he was a valued colleague and longtime member of the broader NBC family. We wish success as he goes forward."

Billy Bush showed up to a law office Friday morning ... to hash out a settlement with the NBC execs who want to give him the ax ... TMZ has learned.

Our sources say an NBC lawyer and a senior executive from NBC News "with full negotiating authority" were across the table from Bush and his attorney, Marshall Grossman.

Grossman tells TMZ the AM negotiations were "positive," adding, "I anticipate a favorable resolution in the near future."

Millions of dollars are on the table ... Billy was just months into a 3-year contract with "Today" and our NBC sources say he was pulling in $3.5 million a year.

We're told NBC made a decision Thursday to sit down at the table because Billy's people made it clear they would sue if the network tried firing him for a cause.

As we've previously reported, Billy was talking openly about the "Access Hollywood" tape in early August and NBC honchos knew what he had said, but had no problem with the tape until it was leaked.

The negotiations are continuing Friday afternoon, and Billy and NBC could be parting company by day's end.

NBC execs had a plan to time the release of the Donald Trump audio to have maximum impact on both the 2nd presidential debate and the general election ... sources connected with the network tell TMZ.

Multiple sources connected with NBC tell us ... top network execs knew about the video long before they publicly said they did, but wanted to hold it because it was too early in the election. The sources say many NBC execs have open disdain for Trump and their plan was to roll out the tape 48 hours before the debate so it would dominate the news cycle leading up to the face-off.

As we reported, Billy Bush was bragging about the tape -- in front of NBC execs at the Rio Olympics -- in early August. NBC says it's only known about the tape for a little more than a week.

We're told the plan was to edit the tape to keep the focus on Trump and not Billy. "Access Hollywood" we're told was not going to air the portion where Trump and Billy got off the bus and Billy goaded Trump and the soap star to hug. Our sources say the tape was going to be "sanitized" to protect Billy as much as possible.

Case in point ... after The Washington Post ran the story, 'Access' aired their footage and cut out the parts where Billy looked worse -- saying things like, "Jeez! Your girl's hot as s*** in the purple!"

We've told you the plan got derailed by Hurricane Matthew. Execs decided the wall-to-wall coverage of the storm would mess up the plan to dominate the news with the Trump tape, so they were going to hold it until Monday. It didn't sit well with some staffers who wanted it out pre-debate, so it was leaked to the Washington Post.

Billy Bush has been all but fired by NBC for his part in the "Access Hollywood" Donald Trump outtakes, but his bosses had no problem with Billy's offhanded remarks about women ... for years.

Sources connected to "Access Hollywood" tell us, Billy and others would talk openly in the newsroom about women ... and some of it's even on tape. We're told some of the comments -- "Man, you look hot today," "Look at her legs," and "Man, she looks hot today!"

Billy was particularly impressed with Gigi Hadid and Taylor Swift's legs. He also, somewhat infamously, asked J Lo point-blank about her butt ... although that comment was at least on camera.

The point is ... we're told no one complained, and Billy wasn't the only one making those kinds of remarks.

What's more ... we're told a number of people knew about the Trump/Bush conversation when it went down in 2005, and again ... no one complained.

People at NBC knew about Donald Trump's crude convo with Billy Bush for at least 2 months ... because Billy was bragging about it back then.

TMZ has confirmed ... Billy was telling NBC staffers in Rio about the tape back in early August, when he was still working for "Access Hollywood." We're told word circulated because Billy made it clear Trump was trash-talking Nancy O'Dell.

NBC News says it didn't know about the outtakes until a week ago Monday, but the word around the network is people knew, including executives at 'Access,' which is an NBC property. We're told those executives had full knowledge of Billy's comments on the tape ... which creates a potential problem if NBC is serious about firing him.

We're told Bush's camp will argue they can't 86 him based on a "morality clause" because execs knew what he had said, and didn't discipline him at the time ... 11 years ago.

Sylvester Stallone's training and weight loss show, "Strong" was jacked from the mind of a personal trainer ... according to the suit the guy just filed.

Robert Fletcher says he created a show called "America's Next Great Trainer" and shopped it around Hollywood in 2014. He says he sent his pitch materials to Stallone's publicist, and also to agents at William Morris Endeavor ... which reps Stallone.

Fletcher thinks it's no coincidence that in early 2016 he started hearing about "Strong" -- the NBC show that lists Sly as one of its executive producers.

"Strong" features male and female trainers competing in various physical challenges -- and in his suit, Fletcher says that's almost a carbon copy of his show idea.

He says it's also fishy that one of the "Strong" trainers is a guy named Todd Durkin. Fletcher says Durkin was attached to 'ANGT' ... but went radio silent in 2015.

He's suing Stallone, NBC, Durkin and other "Strong" producers for at least $7 mil.

"The Biggest Loser" needs to drop more than weight ... its new logo is a total rip-off, according to a new lawsuit filed by former NFL lineman LeCharles Bentley.