By Hernan Nessi

BUENOS AIRES Argentina's consumer prices likely rose by less than double digits in October, a Reuters poll showed on Friday, slowing down after hitting a three-decade high in September.

The poll, which surveyed 19 analysts, showed consumer prices increasing by 9.9% in the month, slowing from the 12.4% rise in August and 12.7% climb in September, though they warned the slowdown would be temporary.

The slowdown comes off the back of October's general elections, analysts said, with Economy Minister Sergio Massa posting a surprisingly strong first-place finish despite the country's deepening economic crisis and radical libertarian Javier Milei trailing close behind.

The two will head to a run-off vote on Nov. 19.

"The election result was a victory for the peso, and that meant that inflation was not in the double digits," said economist Lucio Garay Mendez from local consulting firm EcoGo.

"However, consumer prices are still going up quickly, especially considering the official exchange rate and government controls."

Economy Minister Massa has defended the use of the peso, which has sharply depreciated against the U.S. dollar amid the economic turmoil.

The tightly controlled official exchange rate was devalued to 350 pesos per greenback in August, though it currently trades for nearly three times that on the informal parallel market.

Milei, meanwhile, has pushed to dollarize the economy and abolish the central bank.

"The situation remains delicate and price distortion will continue to accumulate," Garay Mendez said. "Until there is a correction, it will be difficult to slow down the inflationary inertia."

The projections among the analysts surveyed ranged from a minimum rise of 9.3% to a maximum of 13.9% for October.

Latin America's third-largest economy has one of the highest inflation rates in the world, with residents' purchasing power shrinking and poverty climbing.

"Consumer price inflation likely returned to single digits, but only temporarily," said economist Jeronimo Montalvo of Empiria Consultores.

"The effect of August's peso devaluation was diluted, but it seems more inertia is building now than from before the previous exchange rate shock."

The official statistics institute INDEC will publish October's inflation data on Monday at 1900 GMT, when the central bank will also release its Market Expectations Survey (REM).

(Reporting by Hernan Nessi; Writing by Kylie Madry; Editing by Chizu Nomiyama)