Mexico's Senate has approved legislation to implement historic constitutional reform that would open the country's oil and gas industry to foreign investment for the first time since 1938.
In an 85-26 vote, lawmakers passed the last of four packages of laws Monday to end the monopoly held by state oil company Pemex for 75 years in the exploration and exploitation of energy resources.
The Chamber of Deputies must now vote on the measures, which the leftist opposition had tried to modify.
President Enrique Pena Nieto hailed the marathon voting that began Thursday as an example of Mexico's "political civility and maturity".
The leftist Party of the Democratic Revolution and the Labor Party rejected the measures, which were initially approved in December, saying the country would be stripped of its natural resources, especially oil. They warned the law would trigger "expropriation".
The measures set rules for Pemex, which provides a third of the country's tax revenue, and the Federal Electrical Commission to function as "productive state enterprises" with autonomy.
They also pave the way for private production and supply of electricity.
Pena Nieto, who has already scored successes in education, property, finance and telecommunications reform, says the energy reform will modernize Pemex and boost oil production, which fell dramatically in the last decade.
The government also says the reform will benefit the nation by lowering energy costs, creating jobs and reversing the steady drop in oil production.