Even while reviews of her latest film Vanity Fair are trickling in and the offer to direct the next Harry Potter film is under discussion, Mira Nair has begun casting for her next project.

Nair will be directing Rani Mukerji in a screen adaptation of Pulitzer winner Jhumpa Lahiri's The Namesake.

Nair has comfortably straddled both the Asian and American continent, having previously directed an Indian cast in Salaam Bombay, Mississippi Masala and Monsoon Wedding.

Mukerji, whose 'Veer-Zaara' (Yash Chopra) opens at Diwali and Black (Sanjay Leela Bhansali) opens in December, is extremely tight-lipped about her collaboration with Nair. She goes into this project after her ongoing world tour with Shah Rukh Khan and Preity Zinta.

In The Namesake she will play a Bengali girl who ages from her final teen years to the mid-40s. The Namesake is about the Bengali experience in the US.

However, speaking from New York, where she has just returned from the Venice premiere of Vanity Fair, Nair confirms, "Yes, I've signed Rani Mukerji to play the pivotal role of Ashima in The Namesake. I've been wooing her over the phone ever since I saw her in Mani Ratnam's Yuva."

Originally, after Vanity Fair Nair was supposed to go into a different project: a movie adaptation of American playwright Tony Kushner's long political play Homebody/Kabul. However, the New York based filmmaker changed her mind because she wanted to do something Indian after Vanity Fair.

Nair comes to Kolkata next month to finalise the rest of the cast, though the male protagonist — a Bengali ABCD — could be played by an Indian actor in the US.

As for her being roped-in to direct the fifth segment of Harry Potter, though she doesn't deny being approached, Nair says, "It's too early to talk about it. I don't know how it got out on the websites. I've to sit with them, work out dates, etc. Until then I am forbidden from talking about it. Right now I'm fully into The Namesake."

Could The Namesake do for Mukerji what Gurinder Chadha's Bride & Prejudice seems to be doing for Aishwarya Rai — find international success? That remains to be seen.