Ellen's New Squeeze: Portia de Rossi

By Chris Gardner and Ulrica Wihlborg

12/15/2004 at 01:00 PM EST

Just weeks after Ellen DeGeneres's girlfriend of four years, photographer Alexandra Hedison, moved out of the couple's Hollywood Hills home, the talk show maven has a new love interest: Arrested Development star Portia de Rossi, a source tells PEOPLE.

De Rossi, 31, also recently became single after splitting with her girlfriend of three years, singer-songwriter Francesca Gregorini, 31, who is the stepdaughter of former Beatle Ringo Starr.

Although DeGeneres, 46, and de Rossi, who was once featured on Ally McBeal, have been acquainted for some time, their romance came to light at the VH1 Big in '04 awards ceremony in Los Angeles on Dec. 1.

An onlooker reports, "Ellen and Portia seemed totally into each other. Their body language was intense." A spokesman for de Rossi wouldn't discuss her personal life. DeGeneres's rep refused to comment.

DeGeneres and Hedison, 35, met through mutual friends in 2000.