Natalie Maines has filed for divorce from Adrian Pasdar.

Natalie Maines and Adrian Pasdar

Natalie Maines and Adrian Pasdar

The Dixie Chicks singer has cited irreconcilable differences in her petition to end her 17-year marriage to the 'Heroes' actor and she is seeking joint custody of their two sons, Jackson, 16, and 12-year-old Beckett.

While it is unclear why the couple have split, sources told TMZ things are amicable between Natalie, 42, and 52-year-old Adrian.

The pair tied the knot in June 2000, after meeting at Dixie Chicks bandmate Emily Strayer's wedding to first husband Charlie Robison, where Natalie was a bridesmaid and Adrian was a groomsman.

A spokesperson for Natalie said the situation was a "private family matter" and declined to comment.

The 'Wide Open Spaces' singer was previously married to Michael Tarabay from 1997 to 1999, and she previously admitted that going through her first divorce at the same time as bandmate Martie Maguire's marriage to Ted Seidel broke down was what brought them together as a group.

She previously said: "We knew nothing about each other... One day I just burst into the studio and said, 'I'm getting a divorce.'

"And Martie burst into tears and said, 'I'm not happy either.' It broke down a wall between us. We hadn't been honest with each other about our lives outside the Chicks.

"Night after night. Nat and I had facing bunks in our RV and we'd have our curtains drawn and talk. Our divorces made us real to each other."