Former Gov. Enrique Peña Nieto has a clear path to the presidential nomination of Mexico's Institutional Revolutionary Party, or PRI, thanks to the withdrawal of Sen. Manlio Fabio Beltrones, the only other candidate vying to head the ticket in the 2012 elections, from the race.

"With unity and a mission focused on the country, we PRI members are committed to building a better Mexico," Peña Nieto said Tuesday after Beltrones bowed out of the race.

"I am aware of the political professionalism and contributions of Beltrones to the PRI's mission and unity," the 45-year-old Peña Nieto said in a message posted on social-networking sites.

Beltrones, who was trailing Peña Nieto in the polls, said he pulled out as a "contribution to the PRI victory in 2012" and "not as a sacrifice."

"I have decided today not to participate in the internal process for the presidential candidacy, opting to be a man who serves the interests of the country and my party, which I dream of seeing renewed and leading the construction of a prosperous and safe new nation," Beltrones said in a statement published Tuesday in several newspapers.

Polls show the PRI, which governed Mexico from 1929 to 2000, regaining the presidency in next year's election.

Mexico will hold its presidential election on July 1, 2012, electing a successor to President Felipe Calderon of the National Action Party, or PAN.

The leading candidates are Peña Nieto, who is now on a clear path to be the standard-bearer of the Compromiso por Mexico coalition formed by the PRI, the Mexican Green Party, or PVEM, and the New Alliance Party, or PANAL; and former Mexico City Mayor Andres Manuel Lopez Obrador, who heads the ticket of the alliance formed by the leftist Party of the Democratic Revolution, or PRD, the Workers Party, or PT, and the Movimiento Ciudadano.

The PAN, which is going it alone in the election, has not decided on a candidate yet.

Josefina Vazquez Mota, Santiago Creel and Ernesto Cordero are vying for the PAN's nomination.

Compromiso por Mexico announced plans last month to hold a primary election on Feb. 8 to decide its presidential candidate.

There are those in the PRI "who are in a hurry and claim the need for unity to hold on to privileges to guarantee their personal or group interests," Beltrones said, without identifying anyone.

Now "is not the time for ambition," Beltrones, a former governor of the northern state of Sonora, said.

The PRI must "accelerate the pace" of picking a candidate in the wake of its close election victory on Nov. 13 in the western state of Michoacan and the decision by the left to run a single candidate, the senator said.

The process of selecting the PRI's candidate "marks a clear path to unity," PANAL president Luis Castro Obregon told Efe.

"It's encouraging that the majority of the parties are promoting cohesion and unity," Castro Obregon said, referring to Beltrones's decision to drop out of the race and the move by leftist parties to compete in the 2012 election with a common candidate.

Peña Nieto is an attorney who served as governor of Mexico state, which surrounds the Federal District and forms part of the Mexico City metropolitan area.

Some 80 million Mexicans will be eligible to vote for a new president, 628 legislators and thousands of other officials in next year's general elections.