DAVID GREENE, HOST: Over the weekend, the majority of states in Mexico ratified constitutional changes that will allow foreign investment in Mexico's oil sector for the first time in decades.</s>DAVID GREENE, HOST: Here's more from NPR's Carrie Kahn.</s>CARRIE KAHN, BYLINE: Mexico's state monopoly PEMEX has controlled the country's rich oil industry for 75 years. It took lawmakers less than a month to open it up. Not only was the speed of pushing through the politically sensitive constitutional change remarkable, says University of Georgia business professor Tim Samples, but so was the depth of the reform.</s>TIM SAMPLES: It was impossible to imagine the bill would go so far to promoting competition in the energy sector, even just a few months ago it was really difficult to imagine.</s>CARRIE KAHN, BYLINE: If all goes well, Mexico will allow private investors to explore and drill for its precious resource while even allowing foreign oil companies to earn profits off the nation's rich oil reserves.</s>CARRIE KAHN, BYLINE: Samples, who has also worked as an attorney for oil interests, says the world's largest companies, Chevron, BP and ExxonMobil are paying very close attention to what's happening in Mexico.</s>TIM SAMPLES: But they're also shrewd and wise enough to know that important steps lie ahead and they know that devils live in details and that will all be hashed out next year.</s>CARRIE KAHN, BYLINE: That's when the Mexican Congress takes up those devilish details after their holiday break. It's also when the oil reform's vocal opponents get to re-launch what had been nearly daily street protests and demonstrations.</s>CARRIE KAHN, BYLINE: Carrie Kahn, NPR News, Mexico City.
Over the weekend, the needed majority of Mexican states ratified sweeping constitutional changes that would allow for the first time in decades foreign investment in the country's oil monopoly. Pemex has controlled the country's oil industry for 75 years.