The undated picture provided by German car maker Opel shows Italian referee Pierluigi Collina posing in front of an Opel car at the Colosseo in Rome. The world's most recognized soccer official Collina announced Monday, Aug 29, 2005 that he has decided to resign from Italy's referees association in the face of a business conflict. Collina recently signed a sponsorship deal with car manufacturer Opel, the main sponsor of AC Milan. Soccer officials said the agreement caused a conflict of interest and ordered the bald-headed referee to end the arrangement or quit. (AP Photo/Opel) ** EDITORIAL USE ONLY MANDATORY CREDIT **