The 25-year-old will join Auxerre in a €3million deal and has signed a four-year contract with the club.
“We knew we could not keep him [Le Tallec] because of the talent of the player and the financial obligations of falling into Ligue 2,” Le Mans president Henri Legarda told the club’s official website.
“The negotiations were long and bitter because we did not want to take any financial risk, but the satisfaction is great today.”