The 30-year-old spent the last three seasons on the Rossoneri's books after moving from rivals Inter Milan in 2012 when his contract expired, but fell out of favour under manager Filippo Inzaghi last season, enjoying only six appearances in 2015.
Despite the departure of Inzaghi, Muntari was deemed surplus to requirement under new manager Sinisa Mihajlovic ahead of the 2015-16 season.
The former Sunderland and Portsmouth midfielder is expected to play a key role as Victor Piturca's men seek to win the Arabian Gulf League in the new campaign.
The former Steaua Bucureşti manager is reported to be preparing an offer for another Ghanaian Kevin Prince-Boateng.
Muntari, who has earned 83 caps for Ghana, scoring 21 goals since making his debut against Slovenia in May 2002, will be unveiled by his new club on Tuesday.