Barcelona still have the option to sell Turan in any transfer window during the loan period, which is to conclude around the time that the midfielder's five-year contract ends.
Barcelona have confirmed that out-of-favour midfielder Arda Turan has linked up with Istanbul Basaksehir on a loan deal until 2020.
Basaksehir will pay Barca in variables dependent on a number of factors, including appearances and goals, as well as the team's success with Turan at the club.
The club's president Goksel Gumusdag took charge of the negotiations, finally striking a deal with Barca's CEO Oscar Grau late in the week ahead of Saturday's announcement.
Although Turan moved from Atletico Madrid to Barcelona in the summer of 2015, he made his debut in January 2016 due to a Federation Internationale de Football Association transfer ban on the Catalan side.More news: Patterson-UTI Energy, Inc. (PTEN) Analysts See $-0.08 EPS
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After his move to Barca, the authorities in the Istanbul district of Bayrampasa announced that they had named the road where he grew up "Arda Turan Street" in his honour.
"This is not just a transfer for Basaksehir, but a transfer for Turkey".
The fourth-most capped Turkish player will also be hoping to return to his best for the national team after reversing his decision to retire from worldwide football in August.
Turan had not made a single appearance for the current La Liga leaders this term after he was seemingly frozen out of the senior set up by first-team head coach Ernesto Valverde.