Grant and Khan split

Hugh Grant and Jemima Khan have separated, his agent confirmed.

Robert Garlock told US website People.com: "Hugh and Jemima have decided to split amicably."

The pair began dating around three years ago.

Romantic comedy star Grant, 46, who is best known for his role in Four Weddings and a Funeral, had been dating Khan for about three years but had recently dodged questions about whether marriage was on the cards.

Khan, socialite daughter of the late millionaire James Goldsmith, began her relationship with Grant after the breakdown of her marriage to Pakistani cricketer-turned-politician Imran Khan, with whom she has two sons.

The split comes days after the couple attended the London and Los Angeles premieres of his new film, Music and Lyrics.

There have been suggestions that their relationship was in trouble after they were reportedly seen arguing in public.

The pair were seen rowing at Khan's 33rd birthday party held at The George Restaurant in Mayfair, London.

Khan was reportedly overheard joking about Grant's commitment phobia to which he replied she was behaving like a dictator.

Grant, who has never been married, was famously arrested with a prostitute in Hollywood in 1995, while in a long-term relationship with actress and model Elizabeth Hurley.

Grant, famed for his portrayal of foppish Englishmen, recently admitted to not being the "romantic type".

The Hollywood star, who has made his name in a string of slushy movies, described Khan as "very brave" after she spent an hour on the red carpet at the premier of Music and Lyrics.

He said: "I'm not a very romantic man and I'm not a very musical man.... What am I doing in this film? I don't know."

He plays a washed up and commitment-phobe 80s pop star in the new comedy.

A friend of Khan's said Jemima had never thought the relationship would end in marriage "for all sorts of reasons".

He said: "The relationship was finally ended on Friday.

"Both sides felt it was the natural end of the long relationship. Nobody else was involved on either side.

"As far as Jemima was concerned she never really felt the relationship would lead to marriage, although she was extremely fond of Hugh."

He said the relationship had been "fairly rocky" in recent weeks.

A spokesman for the couple said: "It is an entirely amicable split, but both regard it as a private matter and will not be making any further statements."

News of the split comes as Liz Hurley posted the notice of her marriage to Indian businessman Arun Nayar at Sudeley Castle, near Winchcombe, Gloucestershire.

The document announcing the marriage went on public display at Cheltenham Register Office on Friday.

She fled to Sudeley after news broke of Grant's brief liaison with a prostitute in 1995.