Gandolfini, star of HBO's "The Sopranos," (search) had been engaged to Somoza, a writer, since January 2004. While Gandolfini lives in New York, Somoza has moved to Los Angeles, where her grandmother is ailing.
"It was not a case of one dumping the other, as some have reported," Mark Armstrong, the actor's manager, told The Associated Press Friday. "It was very mutual."
Gandolfini, 43, was married to Marcy Wudarski (search) for three years. They divorced in 2002.
He stars as Tony Soprano in the HBO drama, which is set to begin shooting a new season in April.