Angelina Jolie in a scene from 'A Mighty Heart'

Brad Pitt was nervous about asking lover Angelina Jolie to play the lead role in his new movie.Brad - whose company Plan B produced 'A Mighty Heart' which tells the true story of a woman whose journalist husband is murdered - knew Angelina would be perfect to play Mariane Pearl but was worried he would be accused of favouritism. He told Newsweek magazine: "I knew the part had to be played by someone with Mariane's strength and understanding of the world, but I didn't know how to broach the subject."It feels a little like Wolfowitz trying to get his girlfriend a job."Former World Bank president Paul Wolfowitz resigned last month after he was accused of using his position to get his girlfriend a promotion. Brad, 43, also slammed critics who complained when Angelina landed the role of Afro-Cuban Mariane. He added: "I know that people are frustrated at the lack of great roles (for people of color), but I think they've picked the wrong example here."The real-life Mariane, who is now close friends with the 32-year-old actress, revealed she was pleased Angelina was chosen to portray her. She said: "This is not about skin color. I wanted her to play me because I trust her. Aren't we past this?"