Gyan pens permanent deal at Al-Ain
The 26-year-old striker has signed a four-year contract after spending a season on loan with the Gulf club.
"Gyan came to Al-Ain last year on a loan contract and he showed excellent harmony with the players on and off the pitch," the statement said.
No transfer fee was disclosed for Gyan, who scored 11 goals in 37 league and cup appearances for Sunderland after joining from Rennes in 2010 for 13.2 million pounds.
Gyan helped Al-Ain secure the Etisalat Pro-League championship last season, scoring 22 times in 18 matches.