Britney throws on a fresh spring dress and a cowboy hat, going on a shopping spree at Sydney Michelle Boutique in Los Angeles on Thursday afternoon.

Bookmaker William Hill was offering odds¹ of 6-1 that the 24-year-old prince, second in line to the throne, would tie the knot with a female fellow army officer.

But a host of famous and infamous² celebrities³ were not far behind.

William Hill offered 8-1 on Tara Palmer-Tomkinson, a British socialite and friend of the family, 14-1 on Australian pop singer Kylie Minogue and also on US party girl Hilton, the hotel chain heiress.

Wayward singer Spears -- whom he was reported to have been exchanging emails with in 2002 -- was priced at 20-1, British model Keeley Hazell was 22-1 and gutsy Russian tennis beauty Maria Sharapova was 33-1.

Other potential queens quoted included US singer Kelly Osbourne and Paul McCartney's estranged⁴ wife Heather Mills, both at 100-1.

A same-sex civil ceremony was also a 100-1 shot.

William's brother Prince Harry⁵, 22, was tipped to beat him to getting down on one knee. William Hill said Harry was 1-2 to get engaged first while William was 6-4.

They offered odds of 2-1 that William would get engaged between the ages of 28 and 30, 10-1 that he would still be unmarried at 35 and 20-1 that he would become king as a single man.

William Hill said they had expected to pay out over 50,000 pounds (75,000 euros, 100,000 dollars) if William married Middleton.

But British media reported Saturday that the love affair was over.

"We are as shocked as everyone else, if rather more relieved than most as we were preparing to pay out over 50,000 pounds to punters who had backed the couple to wed," said William Hill spokesman Rupert Adams.