According to Hong Kong's Oriental Daily and its sister newspaper The Sun, Michelle Yeoh said she had been contacted for playing roles in both Mission: Impossible 3 and The Lecter Variation, the planned The Silence of the Lamb prequel. Yeoh said she was getting somewhat close to seal the deal with M:I3 and was unexpectedly contacted by the production of The Lecter Variation when she was in Cannes last week. She said it was really hard to choose between these to projects and would leave it to the producers. According to an earlier report, Gong Li was offered a role in The Lecter Variation but Yeoh said the producers would decide whom to cast after they did their test shots. Gong has already joined the film adaptation of Miami Vice.
Update:
According to an article by Taiwanese paper UDN, which was very likely the source for Hong Kong's Oriental Daily and The Sun's stories, Michelle Yoeh and Gong Li are offered with two different roles in The Lecter Variation and there has never been any competition between them. Yoeh is asked to take the female lead and Gong is attached to a supporting role, a Japanese woman who "teaches cultural sophistication to a young Hannibal Lecter."