Venezuelan President Hugo Chavez on Saturday congratulated Mexico's presumed president-elect on his victory in the July 1 balloting and expressed his willingness to deepen bilateral ties.

Chavez "congratulates President-elect Enrique Peña Nieto for having triumphed in last Sunday's elections, according to official results issued by the Mexican electoral authority," the Venezuelan Foreign Ministry said in a statement.

The Federal Electoral Institute, or IFE, confirmed Friday following a recount of more than half the ballots cast that Peña Nieto, of the Institutional Revolutionary Party, or PRI, won the election with 38.21 percent of the vote.

The runner-up with 31.59 percent was leftist Andres Manuel Lopez Obrador, candidate of a leftist coalition headed by the Party of the Democratic Revolution, or PRD, while Josefina Vazquez Mota, standard-bearer of the ruling conservative National Action Party, or PAN, finished third with 25.41 percent of the ballots.

The PRI's rivals say the contest was marred by vote-buying and the Federal Electoral Tribunal still must ratify the results.

"President Hugo Chavez reiterates Venezuela's willingness to work with Mexico on deepening bilateral cooperation for the union of our peoples," the statement added.

The leftist head of state said he intended to keep working with Mexico on the process of constructing the 33-member Community of Latin American and Caribbean States, "thereby strengthening hope for a future of dignity and sovereignty for the region."

Lopez Obrador, who never accepted his defeat by a razor-thin margin to the PAN's Felipe Calderon in 2006, has vowed to formally challenge Peña Nieto's victory, saying the contest was marred by widespread vote-buying in poor areas.

The PAN, for its part, said it will challenge irregularities such as the breaching of campaign spending limits, direct and indirect vote buying and campaigning past the allotted time period in certain areas of the country but will not lodge an overall challenge to the voting result.

Peña Nieto said Friday that "isolated irregularities" could have occurred but that allegations of wrongdoing "must be proven in the (Federal) Electoral Tribunal," which will begin receiving complaints on Monday.

The victory for the PRI, which governed Mexico uninterruptedly from 1929 to 2000, returns that party to the presidency after a 12-year absence.

During its 71 years of largely unchallenged hegemony, the PRI relied mainly on patronage and control of organized labor and the mass media, though it was not above resorting to outright vote-rigging and even violence.

Although many Mexicans remain suspicious of the party due to its corrupt past, the PRI was able to regain power in large part due to spiraling drug-related violence that has left more than 50,000 dead during the presidency of Calderon, who took office in late 2006. EFE