Paris Hilton and her boyfriend of nine months, Benji Madden, have broken up. Hilton publicist Alanna McCarthy said Wednesday that the two "remain very good friends." She wouldn't say more.

Hilton and Madden have been photographed wearing rings with each other's initials. The 27-year-old socialite also joined her boyfriend when he toured with his rock band, Good Charlotte.

The 29-year-old Madden plays guitar, and his identical twin brother, Joel, is the lead singer.

Joel Madden has a daughter with Nicole Richie, Hilton's longtime friend and reality-TV co-star.