Rachel McAdams and Michael Sheen

Rachel McAdams and Michael Sheen have split up.

The 'Midnight in Paris' co-stars have reportedly called time on their two-year romance, a source told Usmagazine.com, though the reasons for the demise of their relationship are not yet known.

Rachel previously revealed she and 44-year-old Michael - who has 14-year-old daughter Lily with ex-girlfriend Kate Beckinsale - started dating after they completed filming on the Woody Allen movie after developing a close friendship.

She said: ''Michael and I didn't get together while we were filming 'Midnight in Paris', which I feel strongly about not doing when I'm working. We became quite good friends, which I think is a great way to start.

''I felt very blessed to have made a Woody Allen film in Paris together.''

And the 34-year-old beauty previously spoke of her belief that communication was very important to making their romance work.

She said: ''You need to trust each other and be able to talk to each other and be best friends.

''Michael and I never spend more than three weeks apart - we rack up a lot of air miles - but you have to be quite adaptable in this business whether you are in a relationship or not.''

Rachel was previously in a two-year relationship with fellow Canadian actor Ryan Gosling but they separated in 2007.

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