09/28/2009 at 07:15 PM EDT
Emmy Rossum's husband, music executive Justin Siegel, has filed for divorce after a year-and-a-half marriage.
Siegel cites irreconcilable differences and seeks spousal support from Rossum, 23, according to the Sept. 25 filing in Los Angeles Superior Court. The couple had no children.
Although no date of separation is listed on the divorce filing, a source says the pair split in August.
Rossum recently has been romantically linked with Counting Crows frontman Adam Duritz, 45. Over Labor Day weekend in a New York restaurant, they "were sitting side by side, kissing throughout dinner," a source told PEOPLE.
A rep for Rossum wasn't immediately available for comment.