Patrick Dempsey is in final negotiations for a role in Bridget Jones's Baby, the third instalment of the Bridget Jones franchise.

According to Deadline, the 49-year-old former star of US drama Grey's Anatomy is set for a role alongside Renee Zellweger, who is once again reprising her titular character.

Dempsey played neurosurgeon Dr Derek Shepherd for 10 years until the character was killed off; as the show's resident heartthrob, he was nicknamed McDreamy by fans.

Bridget Jones's Baby will be his first major role since leaving the popular US medical series.

Plot details for Bridget Jones's Baby, including the part Dempsey will play, are being kept firmly under wraps. However, it is rumoured he will be a love interest for Bridget Jones.

Zellweger, the 46-year-old best supporting actress Oscar-winner for Cold Mountain, starred as hapless Bridget Jones in the 2001 adaptation of Helen Fielding's hit novel Bridget Jones' Diary and its 2004 sequel.

The cast will include Academy Award-winner Colin Firth, who makes his third return in the movie franchise as Bridget's great love, Mark Darcy.

However, Hugh Grant will not be back as dastardly Daniel Cleaver. After appearing in the first two movies, the 55-year-old is not signing on for the third.

The story for Bridget Jones's Baby is apparently based on columns written by creator Helen Fielding rather than her latest novel Mad About The Boy, in which Firth's character has died.

Oscar-winning screen writer Emma Thompson has been enlisted by Working Title to work on the script and Sharon Maguire, who directed the original Bridget Jones's Diary in 2001, returns to helm Bridget Jones's Baby.

Filming is expected to start on Bridget Jones's Baby soon.