Sarah Jessica Parker has reportedly signed up for 'Sex and the City 3'.

Sarah Jessica Parker

Sarah Jessica Parker

The 51-year-old actress, who starred as Carrie Bradshaw on the iconic TV show, Cynthia Nixon (Miranda), Kristin Davis (Charlotte) and Candace Bushnell are expected to start filming on the eagerly anticipated romantic comedy movie sequel after reaching a deal.

A source told RadarOnline.com: "All the women are officially signed up for SATC movie 3. The deal is done and the script has been approved by all the women."

'Sex and the City' is based on the original books - a collection of essays by Candace based on her and her friends' lifestyles.

Sarah came close to skipping the third reunion over issues with the script, but it's understood that "tweaks" have been made to persuade her to get on board.

The insider said: "There was a lot of back and forth. Sarah Jessica Parker was not originally on board because she didn't like the idea of the characters being portrayed in a more mature light. The full green light for 'Sex and the City 3' the movie is really new. Everyone's happy with how things have turned out and they can't wait to get started working together again."

However, it's unclear whether Kim Cattrell will be joining the cast, as according to Radar's report, Candace is listed as being involved instead.

Shooting for the film is expected to start in the summer.

A third 'Sex and the City' film has been rumoured for some time.

And earlier this year, Sarah teased: "[There is] always a possibility, definitely. I don't know whether it's a series or the movie. I think that remains an open question and discussion that will continue until it's been resolved."