Pemex is trying to avert a strike by Mexico's 80,000-member oil workers' union. The oil union is threatening to strike over wage increases. The two sides have a basic agreement, however, the details have yet to be worked out. Originally the union asked for a 15 percent raise and management offered 5.5 percent. Local newspapers said on Thursday that the range had narrowed to between 5 percent and 10 percent. A strike would be the first since Pemex was created with the 1938 nationalization of the oil industry.