The 28-year-old Algerian moved to Ibrox from Charlton Athletic for £2.5m in 2005 after spells with Sheffield Wednesday, Crewe Alexandra and French side Gueugnon.
"A fee has been agreed with the Qatar club in the region of £1.7m," said Rangers manager Ally McCoist.
"There are just bits and pieces to be tied up there. I think that deal is just about done. He won't be playing against Chelsea tomorrow."
The Scot also confirmed that the club have made a bid for Anderlecht's Hungarian defender, Roland Juhasz, but are waiting for a response from the Belgian side.