Argentina's Massa, Milei battle to woo 9 million swing votes

BUENOS AIRES, Oct 24 (Reuters) - Argentina's Peronist economy chief Sergio Massa faces a fierce battle for middle-ground votes with far-right libertarian Javier Milei ahead of a run-off next month, though the center-left runner has his nose in front after a surprise first round win.

Massa, the current economy minister who has helmed the country amid its worst economic crisis in two decades, pulled in nearly 37% of the vote in the general election on Sunday, some 9.6 million people, versus Milei with 30% and 7.9 million.

Up for grabs are 8.8 million votes that went to the three losing candidates, conservative Patricia Bullrich, moderate Peronist governor Juan Schiaretti and leftist Myriam Bregman.

The race could set the future trajectory of Argentina, South America's no. 2 economy, with a polarized battle between Milei's "chainsaw" shock therapy for the economy and Massa's more steady plan, which has though so far failed to solve the crisis.

The country, a major grains exporter and the biggest debtor to the International Monetary Fund (IMF), is battling inflation of near 140%, near zero net reserves, a looming recession and enfeebled peso currency. Markets slid on Monday after the vote.

"Milei and Massa both are going to need to seek alliances with other political sectors," said Shila Vilker, director of the public opinion consultancy Trespuntozero, but added Milei who has abrasively criticized his rivals may struggle more.

"Massa has been proposing very strongly for a long time the idea of a government of national unity. In Milei's case, things seem a little more difficult because he systematically took care to insult every possible rival."

Schiaretti and Bregman, both left-leaning, in theory should shed most of their combined 2.5 million votes to Massa in the Nov. 19 head-to-head. Bullrich's 6.3 million would likely favor Milei more, but moderates in her coalition could shift to Massa.

"We must add people who did not support us, showing what we are going to do and with whom we are going to do it. The idea is to make clear a new government axis, proposals and our teams," a source close to Massa's team told Reuters.

"I understand that Schiaretti's vote is mostly Peronist. More votes may even come from Bullrich," he added.

A source from Milei's team said he was looking to win over Bullrich's vote, despite the fact during one debate he had called her a "murderer", and would look to rally support against the Peronist left allied to Cristina Fernandez de Kirchner.

"He will likely moderate his speech. He will seek to pressure the anti-Kirchnerist voters of Bullrich and Schiaretti," the person said, adding he was looking for a "clean slate" to help bring in conservative allies.

More moderate conservatives, however, may be key.

Centrist Buenos Aires city mayor Horacio Larreta lost the conservative Together for Change's internal primary to Bullrich, but did get nearly 2.7 million votes, many of which shifted to her. He has said he could not back Milei.

Massa since the vote has publicly pitched the idea of a "unity" government and played up his conservative, family-orientated credentials, in contrast to unmarried Milei who has said his closest companions are his sister and dogs.

However, if Milei can win over a large chunk of Bullrich's right-leaning voters, there could be a tight race, especially if the economic situation gets worse. And turnout, the lowest since 1983 on Sunday, could be a factor too.

"We can't save in our local currency, because it's losing value every day, nor can you buy foreign currency, which more or less remains a little more stable," said student Ramiro Vitale.

Luana Molenberg, a 20-year-old worker in Buenos Aires, said she hoped the anti-Milei vote would get behind Massa: "I'm very afraid that Milei will win."

Political analyst Federico Aurelio said that the nearly seven-point gap was an "important boost" for Massa.

"There's a month until the runoff, and we have to see how the economic variables evolve, but both candidates will be competing to be seen as the 'lesser evil' in the fight," he said.

(This story has been refiled to fix a typo in the candidate's name in paragraph 3)