BUENOS AIRES, Sept 21 (Reuters) - Argentina on Tuesday raised the country"s minimum wage to 31,104 Argentine pesos ($316.51) a month starting in September, as persistent inflation eats away at purchasing power. In October, the minimum monthly wage will rise to 31,938 Argentine pesos, and then to 32,616 Argentine pesos in February 2022, the government said. Overall in 2021, the minimum wage will have risen 55.3%, Economy Minister Martin Guzman said on Twitter. "Today, the salary is a little bit more fair," President Alberto Fernandez said. The increase in the minimum wage is in line with inflation. Prices in Argentina have risen 51.4% in the past 12 months. ($1 = 98.2720 Argentine pesos)