SIR Paul McCartney is expected to marry for the third time on Sunday when he and New York heiress Nancy Shevell wed in a civil ceremony in London.

McCartney and Shevell, who posted an official notice of marriage at Marylebone Register Office in central London last month, will marry at that venue before 30 invited guests, a number of reports said.

It is the same venue where McCartney married his late first wife Linda in 1969, at the height of the Beatles’ fame. Linda died of breast cancer in 1998.

The couple has been given special dispensation by the council to marry on Sunday and have chosen what would have been the groom’s former bandmate John Lennon’s 71st birthday for their big day, according to the Daily Mirror.

McCartney’s partnership with Lennon in 1960s Britain produced some of the most famous and enduring pop songs of the past 50 years.

┬áThe bride-to-be left McCartney’s luxury St Johns Wood home on Saturday afternoon looking happy and relaxed. She was dressed in running shoes, leggings, a black cardigan and a powder-blue fleece and told waiting photographers she was heading to the gym, The (London) Times reported.

Florists arrived with two vans filled with flowers, including pastel roses and white hydrangeas. Despite reports the wedding will be a small affair, 192 chairs were seen being carried into the garden.

A row of fridges stocked with champagne stood next to a marquee in the garden.

The Daily Mirror quoted a source close to McCartney as saying, “The wedding is in keeping with the way Paul and Nancy have conducted their entire relationship — low-key, understated and fueled by goodwill.”

“Neither of them want a huge fuss made and the main priority for both was family,” the source added.

Shevell, 51, who is divorced, and McCartney, 69, are believed to have begun dating after his bitter split with his second wife, former model Heather Mills.

McCartney and Mills were wed in 2002 in a lavish ceremony at Castle Leslie in Ireland estimated by celebrity magazines to have cost around $3.2 million.

But four years later they confirmed they had separated, blaming media intrusion into their private lives, and in 2008 the couple divorced.

McCartney has a son, two daughters and a stepdaughter from his marriage to Linda and a daughter from his union with Mills.

Shevell, previously married for more than 20 years to lawyer Bruce Blakeman, sits on the board of New York’s Metropolitan Transportation and is an executive at a New Jersey-based trucking company owned by her father.