"Mexico is one of the ten largest oil producers in the world, the third-largest in the Western Hemisphere, and an important partner in the U.S. energy trade. However, the amount of oil produced in Mexico has steadily decreased since 2004 due to natural production declines from Cantarell and other large offshore fields ... The onus on arresting or reversing production declines falls squarely on the shoulders of Petróleos Mexicanos (PEMEX), the state-owned oil company ... " (Quoted from site)