Fox Star Studios has come on board with Anurag Kashyap's Phantom Films to co-produce filmmaker's upcoming directorial "Bombay Velvet".

The Ranbir Kapoor and Anushka Sharma-starrer is based on Mumbai in era spanning from 1950s to 1970s. It is the first film of a trilogy on how the city became a metropolis.

`We are delighted to partner with Anurag on his next directorial venture 'Bombay Velvet'. What will make this cinematic journey unique will be the presence of Ranbir Kapoor and Anushka Sharma as the lead protagonists," Vijay Singh, CEO, Fox Star Studios, India, said in a statement.

Singh believes "Bombay Velvet" is an example of "high concept cinema".

Officials at Phantom Films are excited about the partnership, says Vikas Bahl of the banner.

"We are looking forward to working together with Fox Star to create a phenomenal cinematic experience of this story for the big screen," Vikas said.

Kashyap, who is set to receive a French honour at Cannes and has earned accolades galore for his short film in "Bombay Talkies", says "Bombay Velvet" has a story that "fascinated" him.

"'Bombay Velvet' is my first film in a trilogy about Bombay before it became a Metropolis. It's a story that has always fascinated me and we have been developing it for about four years, and I am very excited that now its fully ready and we begin shoot this year," he said.

The movie is slated to release on Christmas 2014.