Bayern Munich's Sosa has been signed by Italian club Napoli. "Sosa is going to continue his career at the foot of Vesuvius," Bayern Munich confirmed in a statement.
Sosa won Olympic gold with Argentina in 2008, a year after joining Bayern, with whom he had one year of his contract remaining.
In three seasons in the Bundesliga he has competed in 35 games, scoring three goals.
At Napoli Sosa can look forward to taking part in the Europa League where the Italian team's group rivals are Liverpool, Steaua Bucharest and Utrecht.