Mumbai: Bollywood heartthrob Ranbir Kapoor is keen on ‘Dhoom’  series and has expressed his desire to be part of the hit sequel.

"If another sequel to 'Dhoom' series comes after'Dhoom 3' then I would love to be part of it. It is a very good franchise. Also given the fact that the script is too good," Ranbir said.

Thrill, action, bike chases, handsome thieves, smart and daring stealing plans have been the attraction in the Dhoom series. After the success of 'Dhoom' (2004) and 'Dhoom-2' (2006), there has been much buzz in B-town regarding its third sequel.

The 28-year-old actor wants to do some action films now and build up his muscles.

"Since 'Sawariya' I am in the same way (body shape)  as I am today...following the same continuity. I have never put on or had to lose weight anytime. For me it is difficult to put on muscles because my body type is such that it loses weight easily. So I hope at some point of a time I get an action film so that I can make a good body and put on muscles. So that I can also look if I hit the villain it should look real," Ranbir said.

Ranbir would be seen next in Imtiaz Ali's 'Rockstar' opposite Czech-Pakistani origin model Nargis Fakri. He plays the role of rockstar Jordan in the film which is slated to release this September.

Later he will be seen in Anurag Basu's romantic-thriller ‘Barfee' alongside Priyanka Chopra and Tollywood actress Ileana D'Cruz.