"They are currently split up as they're living on different coasts and their lives are taking a different direction," the source says. "They are still really close and you never know what is going to happen in the future."
After her marriage with manager AJ DiScala ended in 2006, Sigler, 26, was inseparable from Sartiano, 33, a nightlife impresario in New York who co-owns Butter restaurant and the newly opened lounge 1OAK.
The relationship turned rocky recently, and "she went to New York to work on their problems," says a friend of Sigler's. "She was in New York up until a few days ago and that's when it ended." Another friend called the breakup "mutual. They have both accepted it and are doing their own thing. They're still very close and share so much love for each other."
Sigler stepped out with gal pals on Tuesday night at the Svedka-sponsored launch of philanthropic fashion campaign for Heal the Bay at Fred Segal in Santa Monica – and her attitude about the future was telling. She told PEOPLE of her plans for the summer: "I'm going to Coachella. It's gonna kick off my summer fun with the girls! It's all about me right now. And I like that. I've never had that in my life."