AceShowbiz - Kate Winslet and Sam Mendes' marriage was rocked by arguments about the director's friendship with British actress Rebecca Hall, according to U.K. reports. The "Titanic" star and her "American Beauty" director husband announced their split on Monday, March 15, bringing their seven year marriage to an end.

According to recent reports, the pair struggled to work together while filming "Revolutionary Road" and drifted apart after the movie wrapped. And new claims in several British newspapers suggest Winslet was furious about the amount of time Mendes spent with "Frost/Nixon" star Hall after he cast her in two of his plays.

A source tells U.K. newspaper the Daily Mirror, "Sam is a huge admirer of Rebecca's work. He can be quite a lovely at times and really worked well with her, which would obviously wind Kate up. There's no suggestion of anything untoward but undoubtedly the friendship didn't help mend the struggling marriage. They are most definitely just friends. To suggest anything else is wide of the mark."

And the publication adds that Winslet's decision to stay in America to star in a U.S. TV drama instead of returning to her native U.K. with him for his filming commitments caused a deeper rift between the couple. The insider says, "Sam raised several questions over whether she should be doing it, insisting she was above a TV script, and it wouldn't progress her career. Not surprisingly, Kate went ballistic."