ROME, May 21 (AFP) - Renato Ruggerio, the former head of the World Trade Organisation (WTO), has been named to take over the chairmanship of Italian oil/gas giant ENI, informed sources said Friday. Ruggerio will replace Guglielmo Moscato in the post, the source said. ENI's chief executive will remain Vittorio Mincato. A former diplomat, politician and Fiat board member, Ruggerio left the WTO on May 7 at the end of his mandate, leaving a void that is being fought over by Thai Deputy Premier Supachai Panitchpakdi and former New Zealand prime minister Mike Moore. The Italian press has been speculating about Ruggerio's appointment to ENI, Europe's third-biggest oil group, ever since a meeting on Wednesday between him and Italian Prime Minister Massimo D'Alema. The Italian government holds 36.3 percent of the company, which gives it influence in the naming of members of ENI's management.  