The Environmental Protection Agency (EPA) is assembling a panel of experts from the automobile and oil industries, environmental groups and state governments to decide whether to delay implementation of a rule requiring most of the sulfur to be removed from diesel fuel by 2006. The fuel-sulfur brouhaha is the primary undercurrent of conflicting agendas between the auto and petroleum industries — and is an issue that isn't likely to see quick and easy resolution.Corp., largely through its membership in the increasingly influential Diesel Technology Forum, is pushing to loosen the nation's clean-air rules to allow for wider use of diesel engines. But to have even a prayer of meeting tough new emissions legislation slated for phase-in beginning in 2004, diesels must have low-sulfur fuel. The sulfur-reduction rule is one of the few Clinton administration environmental regulations that the Bush administration supports. Both automakers and environmentalists argue that sulfur removal is necessary to allow the introduction of cleaner-burning diesel (and gasoline) engines.