Turkish media reported that Barcelona will keep paying half the player's salary but Basaksehir, who top the domestic standings, said there were still issues to solve.
"Although we have agreed in principle on many issues, there are still some steps to be taken. My team is in talks with the player's agent and Barcelona club officials," club chairman Goksel Gumusdag said.
"I hope they will come back with a positive result," he added.
Since moving to the Nou Camp in 2015 in a 34 million euro (29.98 million pounds) deal from Atletico Madrid, Turkey international Turan has struggled to hold down a first-team place, scoring 19 goals in 53 appearances in all competitions.
The 30-year-old has not played for Barcelona this season.
(Reporting by Ece Toksabay, editing by Ed Osmond)
