LONDON (Reuters) - British pop star Robbie Williams has become a father for the first time, announcing the arrival of a baby girl - Theodora Rose, "affectionately known as Teddy".

The 38-year-old singer said his daughter was born on Tuesday, weighing 7 pounds 4 ounces.

"Baby, mummy and daddy are all rockin..." Williams said in a message on his website late on Tuesday. "Thank you for your best wishes."

The girl was born in London, British media reported.

Williams announced in March that he and his wife Ayda Field were expecting their first child. Williams married the actress at his Beverly Hills home in 2010.

Williams forged a successful solo career after leaving British boy band Take That in 1995, and signed one of the world's biggest music deals with EMI in 2002.

He has sold over 60 million albums as a solo artist, rejoining the boy band in 2010.