Producer Pritish Nandy has roped in Vidya Balan and Farhan Akhtar for "Shaadi Ke Side Effects", a sequel to 2006 hit film "Pyaar Ke Side Effects". He says a fresh pair was needed for the romantic comedy and that filming would start at the year-end.

"We were working on the script. We do everything in the end. Most people get things done quickly later it is delayed. The film will go on the floors by the year-end and is scheduled to release next year," Nandy told.

" 'Shaadi Ke Side Effects' is a romcom. Vidya will be playing a Delhi girl and Farhan will be playing a Bombay boy," he added.

Produced under the banner of Pritish Nandy Communications, "Pyaar Ke Side Effects" was the directorial debut of Saket Chaudhary. Audiences not only enjoyed the film, but also liked the unusual pairing of Rahul Bose and Mallika Sherawat and their on-screen chemistry.

Chaudhary will wield the megaphone for the sequel too.

On the fresh pair of Vidya and Farhan, Nandy said: "Our idea was to cast an unusual couple. Besides, both Vidya and Farhan are actors. I like the fact that we work with actors."

"This film demanded for fresh faces. We always had Vidya in our mind for 'Shaadi Ke Side Effects'. I believe she really liked the script," he added.

"The story moves ahead from where Trisha and Sid left - they get married and what changes come in their married life, the transformation in their relationship and nd how they tackle the changes," said Nandy.