Britney Spears is so desperate to marry she has been shopping for engagement rings alone.

The 28-year-old star is currently dating agent Jason Trawick, and there have been persistent rumours the pair are planning to wed next year. They are not currently engaged, but Britney is apparently keen to get a ring on her finger before the end of the year.

The star was spotted perusing diamond sparklers in upmarket jewellery stores in Beverly Hills on December 9. "Britney is ready to marry Jason. She wants to be with him 24/7," a source said.

Britney has already sought the approval of her two sons with ex-husband Kevin Federline — Sean Preston (4) and three-year-old Jayden James — and was delighted when they agreed to the union.

She has now set her sights on a new life with Jason, and wants him to take a step back from his career to fully embrace family life. Jason represents stars including Paris Hilton and Hilary Duff, and Britney is concerned his schedule is too hectic at the moment.

"His career is demanding," a source told In Touch Weekly magazine. "He can be on the phone or on his computer at any hour, day or night, and Britney finds that she?s competing with his work for attention. Britney doesn't want to marry a workaholic."

The star is also struggling to come to terms with the judge's ruling that the co-conservatorship her father, Jamie Spears, and lawyer, Andrew Wallet, have over her personal and professional affairs will stay in place.

The pair were granted the order for two years following Britney's meltdown in 2008. She had hoped it would end next month, and is devastated it has been extended for an unspecified amount of time.

"Britney is very upset about the conservatorship being extended," a source told America's OK! magazine. "She feels very duped by the people around her."

Jamie will continue getting $16,000-a-month for looking after his daughter under the new arrangement.