MEXICAN President Carlos Salinas de Gortari ordered state owned Petroleos Mexicanos to close the 105,000 b/d 18th of March refinery in the northern Azcapotzalco district of Mexico City in a step to cut air pollution. Pemex recently was fined for excessive pollution at the plant. Closure will cost $500 million. Plans call for a 300,000 b/d refinery to be built an undisclosed site elsewhere in Mexico. The action will cause a temporary increase in Mexican gasoline imports.