05/12/2004 at 12:00 PM EDT
Kiefer Sutherland has filed for divorce from his wife of nearly eight years, Elizabeth Kelly Winn Sutherland, citing irreconcilable differences, according to papers filed Monday in Los Angeles Superior Court.
The papers also state that the two, who have no children together, have been separated since 1999.
As PEOPLE reported in 2002, Sutherland, already a veteran of a broken marriage and a famously ill-fated engagement with Julia Roberts in 1991, was finalizing the divorce from Winn, now 42, a former model and a divorced mother of two sons.
Explaining why the marriage had gone sour, Sutherland told TV's Entertainment Tonight: "I got more involved in my life than ours."
Still, friends told PEOPLE the 24 star had a close relationship with stepkids Julian, now 13, and Timothy, 10.
The actor also has a 27-year-old stepdaughter from a previous marriage (from 1988-90) to actress Camelia Kath. They also have a young daughter together, named Sarah Jude, reportedly named after actress Sarah Jessica Parker and singer-songwriter Jude Cole.
Last weekend in Edinburgh, Scotland, Sutherland, 37, dressed in a tartan kilt and knee socks to attend the wedding of the stepdaughter, Michelle Kath, to actor Adam Sinclair, also 27.