A guest appearance from Britney Spears has helped US sitcom How I Met Your Mother to its highest-ever ratings.

The Toxic star starred as a doctor's receptionist in the CBS show, with her cameo boosting the show's viewing figures to 10.6 million on Monday night, up from the third season's usual figures of 7.8 million, according to Nielsen Media Research.

How I Met Your Mother, created by Carter Bays and Craig Thomas, sees Ted Mosby telling his children about the events that led up his falling in love with their mother, with Josh Radnor playing the young Ted in flashback while Bob Saget voices scenes featuring Ted as an old man.

And in playing a character with a crush on Ted, Britney also scored highly among US television critics, with the Associated Press news agency commenting: "Britney the Trainwreck showed how she can still be Britney the Performer."

The New York Post newspaper said: "Brit looked slim, (OK she was behind a desk), trim and gorgeous," while the New York Daily News added: "Spears proved she can act every bit as well as she can sing."

Despite her career prospects improving, Britney's legal troubles have continued, with a judge yesterday dismissing a challenge to the conservatorship ruling that gives the pop star's father control of her assets.

Jon Eardley, an attorney claiming to represent Britney, said she had not been given the requisite five days of notice before control of her estate was transferred to her father James and lawyer Andrew Wallet.

However, US district judge Philip Gutierrez rejected Eardley's appeal as the conservatorship of Britney's affairs remains temporary and Eardley also has no proof that he is the singer's legal representative.

26/03/2008 09:35:10