Borussia Dortmund's Japan international midfielder Shinji Kagawa has joined Besiktas on loan for the rest of the season, the Turkish club confirmed.
The 29-year-old former Manchester United player had reportedly been a target for struggling French club Monaco.
Besiktas said Kagawa would be "a part of its team on loan until the end of the season".
Kagawa had earlier passed a medical examination after arriving in the city on Thursday to complete the deal.
Turkish media previously reported that the club had the option to buy the player but Besiktas made no reference to this in its short statement.
Kagawa helped Dortmund win the German league and cup double in 2012 before spending two years at United.
He returned to the German club in 2014, but has fallen out of favour under coach Lucien Favre.