Britney Spears was beaming when she showed off her new engagement ring to the world. Britney Spears will be marrying her third husband, Jason Trawick, who once was her manager.

Trawick confirmed that the couple were indeed planning to get married to Access Hollywood yesterday on his 40th birthday: 'Yes, we are engaged,' A source told US weekly that he had proposed to her with a Neil Lane ring which featured a three carat stone and pave diamonds on the band. The source said, 'It's very traditional. He picked out something he knew she would love' whilst another stated, 'He surprised her after she gave him his gifts and after they had cake last night'. Before they planned the big celebrations in Las Vegas, Spears tweeted: 'Still glowing! About to jump on a plane to Planet Hollywood in Vegas. Throwing a Bday Party for Jason at Chateau Night Club. So fun. Xxoo'. This will be the third marriage for Spears after she previously married Jason Alexander for 55 hours as well as Kevin Federline.

The pair have been dating since early 2009 when Trawick, who was her agent at the time, began to see the star. He stepped down from the role in May and the two were seen making love together in Spears' new video for single 'Criminal'. The couple are currently enjoying some time off after Spears recently finished her 'Femme Fatale' world tour.