The announcement of the deal was made by the Ukraine club on Sunday via their official website.
However, despite purchasing the player in full, Tuttomercatoweb have reported that they have agreed that his former side will receive a percentage of any future transfer for the 24-year-old.
In 2011 the midfielder had looked set for Bundesliga side Schalke after a similar period on loan but the German side pulled out of the deal with Avelar making just three first team appearances.
Last season the Brazilian made 20 appearances in Serie A whilst helping the club to a respectable 11th placed finish but is yet to score for the Isolani.
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