Mexico has changed a plan to curb oil exports as fires at two Pemex refineries have affected local demand for the commodity. According to Pemex employees who spoke to Bloomberg, the company had notified some U.S. buyers of its crude that it could offer additional cargos for May. Earlier this month, reports said Pemex would reduce the rate of exports in order to feed local refineries, with Reuters putting the size of the cut at 436,000 barrels daily. For May, the export reduction was seen at 330,000 barrels daily. The reduction in oil exports…