By Nelson Renteria and Michael O'Boyle SAN SALVADOR, Feb 3 (Reuters) - A former Marxist guerrilla leader who fell just shy of an outright victory in El Salvador's presidential election said on Monday he would court centrists ahead of a March run-off vote and ruled out a swing to the radical left. Salvador Sanchez Ceren, a top leader of the Farabundo Marti National Liberation Front (FMLN) rebel army during El Salvador's civil war, won nearly 49 percent of votes in Sunday's first round, just short of the 50 percent needed to avoid a run-off. He will now face off on March 9 against Norman Quijano, the conservative former mayor of the capital, San Salvador, who took almost 39 percent of the vote and wants to deploy the army to fight powerful street gangs. To ensure a victory in the run-off, Sanchez Ceren will need to lure some of the votes that went to Antonio Saca, a former president and right-wing candidate who came in a distant third on Sunday. Sanchez Ceren on Monday pledged to negotiate with Saca, adding that he would reach out to smaller parties. Quijano, however, insisted the ex-rebel will swing El Salvador to the radical left and bow to Venezuela's influence. The FMLN candidate said before the election that he would seek to join Venezuela's Petrocaribe oil bloc, which furnishes mainly leftist allies with cheap energy, but on Monday ruled out a swing to the South American oil giant's socialist model. "That is an old wives tale," Sanchez Ceren, 69, said in a TV interview. "Our model is based on what the people of El Salvador want. We will not just copy others." The FMLN turned into a political party at the end of El Salvador's 12-year civil war in 1992, and it first won power in 2009 after it toned down some of its more radical proposals. Sanchez Ceren was vice-president in the government and his campaign was helped by its popular welfare policies, including pensions and free school supplies. The regional influence of Venezuela's socialist government is set to be a major issue in the final race. "The FMLN's proposal is based on handing over national sovereignty to Venezuela," Quijano told local television. Ceren said he would negotiate with Saca, who drew about 11.4 percent of votes in Sunday's vote. Saca broke away from Quijano's Nationalist Republican Alliance (Arena) party after he left office, and it is unclear whether he and his supporters will back Sanchez Ceren in the run-off. The Universidad Centroamericana estimates that while about 60 percent of Saca's supporters would likely opt for Quijano in the run-off, around 25 percent would go with Sanchez Ceren. That would be enough to give the leftist a clear win. POVERTY, VIOLENCE El Salvador remains deeply divided between left and right and the rise of violent street gangs has been spurred by persistent poverty and sluggish economic growth. The country is the most dependent in Central America on money sent home by migrants working in the United States - those remittances account for nearly one-fifth of the economy. Quijano's pledged to deploy the army against street gangs, which control poor slums across the country. But the campaign failed to draw in many independent voters, unlike in neighboring Honduras, where conservatives recently won with a similar plan. "Going after the gangs would be like returning to the repression before 1992," said Denise Lopez, a 22-year-old student. Sanchez Ceren opposes the idea and is instead promising to forge a political pact to end the gridlock that has kept a divided Congress from carrying out reforms to tackle crime and weak economic growth. A rural teacher before the civil war, Sanchez Ceren joined the FMLN and became one of its leading commanders as it fought a series of U.S.-backed conservative governments. About 75,000 people were killed in the 12-year conflict.