Mexico's general elections took place in a "calm, respectful and orderly" manner, the Organization of American States, or OAS, observer mission said.

The electoral process that culminated with Sunday's presidential, legislative and local elections was a "success," the observer mission, led by former Colombian President Cesar Gaviria, said in a statement.

The improvements made by the Federal Electoral Institute, or IFE, to the Preliminary Election Results Program, or PREP, provided "adequate security measures and speed in the transmission (of figures) based on a considerable technological infrastructure," the OAS observer mission said.

The "quick count," a sample of more than 7,000 ballots on which the first preliminary results were based, was done "in a professional manner in accordance with the technical program established and released by the IFE as established by the law," the OAS observer mission said.

"Mexico has a robust and trustworthy elections system today, equipped with a significant number of controls, which, once the physical count of ballots has taken place, should allow it to demonstrate trust in the electoral system stemming from the reforms implemented starting with the 2006 election," the OAS observer mission said.

Institutional Revolutionary Party, or PRI, candidate Enrique Peña Nieto won the presidency, taking nearly 38 percent of the vote, while Andres Manuel Lopez Obrador, candidate of the leftist Progressive Movement coalition, won about 32 percent of the vote, with more than 90 percent of the ballots counted.

Governing National Action Party, or PAN, presidential candidate Josefina Vazquez Mota, the only woman in the race, came in third, getting 25.37 percent of the vote. EFE