Mexican President Enrique Peña Nieto signed a political-electoral overhaul that will allow the formation of coalition governments and the immediate re-election of federal lawmakers.

In a ceremony Friday at the Chapultepec Castle, Peña Nieto described the overhaul as a "momentous (step) toward the consolidation of Mexican democracy" that will bolster the government's capacity to forge agreements and push through far-reaching changes.

Beginning in 2018, the winning party in a presidential election will be able to form a coalition government with one or more political groupings in Congress.

In such a case, the Senate must approve all Cabinet appointments except for the secretaries of defense and the navy.

The overhaul also establishes a new autonomous National Electoral Institute that will replace the current entity responsible for organizing federal elections and also assume some duties currently carried out by state-level agencies.

Under the new rules, senators at the national level will be able to be re-elected for up to two consecutive six-year terms, while lower-house lawmakers will be allowed to serve up to four consecutive three-year terms.

The overhaul also allows the re-election of local lawmakers and mayors and requires parties to nominate women for 50 percent of candidacies in legislative races.

The president and state governors will continue to be limited to a single, six-year term.

Federal and local election results also may be nullified for various reasons, including when a party exceeds campaign spending limits by 5 percent or makes use of funds of illicit origin.

In addition, the overhaul makes the office of federal Attorney General autonomous and establishes that Mexico's top prosecutor will be appointed by the Senate for a nine-year term.

The conservative opposition National Action Party, or PAN, demanded the political-electoral changes in exchange for joining Peña Nieto's Institutional Revolutionary Party, or PRI, in supporting a recently approved energy overhaul.

The centrist PRI needed the PAN's support due to staunch opposition by the left to ending state oil company Petroleos Mexicanos' monopoly on crude production. EFE