Acerbic comedian Joan Rivers announced Thursday that she is replacing Donna Rice as the print and TV spokeswoman for "No Excuses" sportswear. "It was a tossup between me and Lady Di. I guess the real princess won," Rivers says in the advertising campaign. Rivers, clutching her Yorkshire terrier, Spike, appeared at a news conference in New York, slipping off her black sable coat and modeling the company's jeans, denim jacket, white T-shirt and sneakers. Asked if she'd ever met Rice, Rivers quipped: "We don't run in the same circle." Asked how much she'd be paid, she replied: "They're dressing me and my daughter and the entire University of Pennsylvania." Her contract with the jeans maker runs a year. "And then," she said, "we'll talk." Rivers refused to comment on the progress of her $50-million libel suit against Gentlemen's Quarterly and columnist Ben Stein.