Former Beatle Paul McCartney is engaged to New York socialite Nancy Shevell, his girlfriend of nearly four years, his publicist said Friday. It will be the 68-year-old pop legend\'s third marriage. His first wife, Linda, died from breast cancer in 1998 and he then wed ex-model Heather Mills in 2002 before divorcing her in 2008. \"We\'re all thrilled for him,\" McCartney\'s spokesman Stuart Bell said, confirming the engagement but giving no further details. Mills and McCartney\'s marriage ended in a bitter divorce three years ago. She was awarded £24.3 million pounds (then $48 million, 30.8 million euros) in an accord finally hammered out after prolonged and acrimonious negotiations. McCartney married Mills in a lavish ceremony in Ireland in June 2002, four years after Linda, a photographer and animal rights campaigner, died from breast cancer.