Celebrity Gossip's

Britney Spears finally appears to be acting like a new mum.

The pop star, who recently made headlines for a rash of less-than-motherly hard partying, fell asleep in a Las Vegas nightclub shortly after leading the New Year's Eve countdown, her manager said.

"By about one o'clock, she was just done, so we took her out," Spears' manager, Larry Rudolph, said today.

"She was not drunk. She was just tired and falling asleep."

Rudolph denied reports circulating on gossip web sites that Spears, 25, collapsed shortly after midnight and was carried out by bodyguards.

The star was hired to host the festivities at Ceasars Palace's Pure nightclub.

Rudolph said Spears walked out of the club and did not seek medical attention.

"There is nothing out of the ordinary here," he said.

Spears was travelling with her two sons, three-month-old Jayden James and one-year-old Sean Preston.

She filed for divorce in November from her husband of two years, Kevin Federline.

In a statement on her web site posted earlier this month, Spears noted that in recent nights out - one in which she flashed her apparent lack of underwear to the paparazzi - she may have taken her "new found freedom a little too far".