Marion Cotillard has revealed her 'Dark Knight Rises' character is a ''good guy''.

The 36-year-old actress has confirmed she will play Miranda Tate - an ecologically-minded businesswoman - in the third and final Christopher Nolan-directed Batman film, despite speculation she was lined up to star as Talia, the daughter of Liam Neeson's alter-ego Ra's Al Ghul.

Speaking about her character, she said: ''She is fascinated by Wayne Enterprises. They go through difficulties, and she wants to help provide the world clean energies. She's a good guy.''

Due to Marion's commitment to 'The Dark Knight Rises', the brunette beauty was unable to spend as much time filming director Jacques Audiard's forthcoming drama movie 'Rust and Bone' - which sees her play a paraplegic whale trainer - and she admitted the helmer was ''sometimes not very happy''.

In an interview with The Hollywood Reporter, she added: ''It was frustrating.''

Jacques explained: ''At one point, I was afraid. So I said to myself: 'We don't know each other; we don't know the character she plays except in bits and pieces. Let's make a virtue of this.' That's exactly what we did, and it worked.''