Biomet ( BMET) chief Dane Miller resigned Monday. The Warsaw, Ind., joint replacement company said general counsel Daniel Hann will act as CEO on an interim basis. Miller, 60 years old, was one of Biomet's four co-founders and has been CEO since the company was formed nearly 30 years ago. Biomet said he "informed the board of his decision to retire" but offered no further insight. The move comes just a week after Biomet posted quarterly numbers that missed Wall Street's revenue target for the second straight period. "I believe in Biomet and its team members, and their ability to continue to deliver quality products and enhance shareholder value," Miller said. "As I begin a new stage in my life, I will always be grateful to have worked with the great people at Biomet and to have played a role in its growth and success." Early Monday, Biomet shares slipped 40 cents to $33.92.