The Turkish club announced Tuesday it has reached a $10.5 million deal with the Doha-based team, without revealing further details.
Fenerbahce, the Turkish champion, is implicated in a match-fixing scandal. More than 30 people, including Fenerbahce President Aziz Yildirim, have been jailed as part of the ongoing investigation.
Former Marseille forward Niang is the fifth foreign player to leave the club this summer after Nigerian Emmanuel Emenike, Daniel Guiza of Spain, Diego Lugano of Uruguay and Andre Santos of Brazil.
The 31-year-old, who has played 52 times for Senegal, scored 15 goals in 31 matches for the Istanbul club last season.
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