Paul McCartney is to marry for the third time, his publicist has announced, confirming earlier reports.

The former Beatle, 68, will tie the knot with Nancy Shevell, 51, a New York socialite and businesswoman, whom he has been dating for four years.

"I can confirm it is true. We are all thrilled for him," McCartney's publicist said, declining to give further details.

A source close to Nancy Shevell had told People magazine: "Nancy and Paul are getting married...Very exciting. They have the right chemistry. They're both cool, chilled out and optimistic."

McCartney's first wife, Linda Eastman, a photographer, died from breast cancer in 1998.

They married in 1969 and had three children together, Mary, 41, Stella 39, and James, 33.

Eastman already had a daughter, Heather, 48. Last month, McCartney paid tribute to his wife.

"She is a very powerful memory because I was married to her for nearly 30 years. Now, in my relationship with my new girlfriend, Linda is a powerful presence, and I am lucky that Nancy recognises that and is a big admirer of her work."

McCartney married Heather Mills, a former model, in 2002, with whom he had his fourth child, Beatrice.

The couple split in 2006 after a turbulent marriage.

They finally divorced in May 2008, and McCartney paid pounds 24.3million in the settlement.