Custody talks kept diva Mariah from Rock Center show

Mariah Carey seemed to be the mother of all divas Tuesday as she kept her fans waiting in the freezing rain in front of the Rockefeller Center Christmas tree — but sources blame it on estranged hubby Nick Cannon’s legal team for keeping her tied up in custody talks.

Sources close to Carey say it was all Nick’s fault that Carey showed up three hours late to Rock Center, where the audience had already left, and NBC execs angrily told her to go home.

Carey had a 7 p.m. call time Tuesday to pretape “All I Want for Christmas Is You” for the 82nd annual “Christmas in Rockefeller Center” tree-lighting show airing Wednesday. “She was going to be backed by an adorable troupe of child ­dancers clad head-to-toe in snow-white winter-wear,” a source told The Post’s Kirsten Fleming.

She’d also been scheduled for a 9 p.m. taped promo that would have featured her riding in a horse and carriage on Fifth Avenue, for which NBC had a permit to close traffic lanes.

Instead, Carey was holed up in a nearby hotel room on the phone with Cannon’s team, arguing over custody of twins Monroe and Moroccan Scott.

“The talks were about custody and seeing their kids,” a source told Page Six, adding that it was Cannon’s team that made Mariah late. “What she went through was ridiculous. People in [Cannon’s] camp knew full well where she had to be. She had even stayed in a hotel a block away because she was worried about traffic.”

But once Carey finally arrived, “NBC had enough and canceled her after twiddling their thumbs for hours.” After the network pulled the plug, the singer made frantic cellphone calls begging NBC to “bring the audience back.”

By 10:30 p.m., most fans, who had been issued free tickets to support the 20th anniversary of the release of Carey’s “All I Want for Christmas Is You,” had trudged home and the production crew had packed up.

Carey tweeted on Wednesday, “Last night’s situation was beyond my control. I apologize to all that showed up, you know that I would never want to disappoint you.”

But NBC confirmed Carey was still performing live Wednesday to open the national broadcast.

Carey’s rep declined to comment on her “personal life.” Cannon’s lawyer didn’t get back to us.