Marg Helgenberger, who stars in "CSI," has taken the next step to end her marriage.

The 50-year-old actress filed for divorce Tuesday, March 24 from her husband, Screen Actors Guild president Alan Rosenberg, citing irreconcilable differences, reports

In the papers, which were filed in Los Angeles County Superior Court, Helgenberger is seeking spousal support and has requested to split attorney fees.

Helgenberger met Rosenberg, 58, in 1984 on the set of her soap "Ryan's Hope" and struck up a friendship since Rosenberg was married at the time to actress Robin Bartlett. Four years later, after his divorce, he reconnected with Helgenberger again in a line for a West Hollywood bank.

They eloped in 1989 and have an 18-year-old son together, Hugh. In December 2008 they separated.

Rosenberg has appeared on "L.A. Law," "Cybill," "Chicago Hope" and on two episodes of his estranged wife's series "CSI: Crime Scene Investigation," in which she plays Catherine Willows. She won an Emmy in 1990 for her supporting role K.C. Kolowski on "China Beach."

After Rosenberg and other leaders of SAG rejected producers' "final offer" in February, they've been holding informal talks with studio execs in a bid to reopen contract negotiations.