Slaven Bilic is set to become the manager of Besiktas on a two-year contract worth a reported €800,000 (£680,500) per-season.
The Turkish club released a statement on the Istanbul Stock Exchange confirming they are in talks with the former West Ham defender.
The statement read: "We are in talks with Slaven Bilic for the Besiktas managerial role."
The Besiktas director of football Onder Ozen and board member Ahmet Nur Cebi reportedly travelled to Zagreb to secure the deal after the Croatian was sacked by Lokomotiv Moscow last week.
Bilic, 44, took charge of Lokomotiv last summer but could only guide the club to a ninth-placed finish in the 16-team Premier League, the club's worst finish since 1991.