Mulligan in awe of DiCaprio's generosity

Carey Mulligan was "blown away" by Leonardo DiCaprio's generosity when she tried out for The Great Gatsby after he improvised lines as three different characters to improve her audition.

The British actress saw off competition from the likes of Scarlett Johansson and Blake Lively to win the coveted part of Daisy Buchanan in Baz Luhrmann's upcoming adaptation of F. Scott Fitzgerald's classic novel.

But the actress admits plenty of credit is due to the movie's lead actor DiCaprio, who went out of his way to help her get cast.

She tells Collider, "Leonardo is the most incredible actor on the planet, with a couple of people alongside him... I walked away from my audition for that and I couldn't believe that I'd been acting with him.

"We did 15 takes of one scene. He didn't really have much dialogue as Gatsby, and the camera was never on him, but he played three other characters. He'd say a line as Gatsby, and then he'd jump up and play Tom Buchanan.

"We were doing the scene with the cameras over my shoulder, and he was lighting a cigarette for me and looking at me. It was all me, and he didn't have any words, and he was improvising stuff to say, just to help me. I was like, 'Leonardo DiCaprio doesn't need to be helping me in this audition.' He was auditioning girls all day. I was so blown away by how generous he was, let alone being amazing to act with."