The Mexican government has announced plans to eliminate a tariff on imports of US and Canadian natural gas earlier than scheduled to compensate for a potential energy shortage in northern areas of the country. The 4% tariff will be scrapped July 1. If Mexico had followed the timetable spelled out under the North American Free Trade Agreement (NAFTA), the tariff would have remained in place until 2003. The government had planned to eliminate the tariff at the end of 1999, but moved up the date to the middle of the year to boost supplies of natural gas in the rapidly growing industrial areas of northern Mexico. "Eliminating the tariff will improve the quality of energy available both …