The `Dexter` co-stars - who plays brother and sister Dexter and Deb Morgan in the US drama series -separated some time ago and are now starting proceedings to legally end their union. Their representatives confirmed to Entertainment Weekly: "Having been separated for some time, Jennifer Carpenter and Michael C Hall have filed for divorce." The couple - who married almost two years ago on New Year`s Eve (31.12.08) - did not give a reason for their separation but insist it is an amicable split. However, insiders on the set of `Dexter` told `Access Hollywood` that the pair had been squabbling for some time, with the 39-year-old actor - who successfully battled cancer earlier this year - speaking at length about their problems. Despite the claims, Michael has previously insisted his relationship with Jennifer, 31, did not affect their work. He said earlier this year: "We certainly pride ourselves in being professionals. We work on the same show but we`re not in every scene together. We don`t see each other on set as often as you`d think." Michael was previously married to theatre actress Amy Spanger for five years until 2006.