The 29-year-old has signed a three-year deal and will be paid an annual salary of nine million euros ($10.4 million), plus a "loyalty bonus" of three million euros a season, the club said.

"I've played here before. There was an incredible atmosphere," said Sane after arriving in Istanbul.

"Honestly, the fans were very loud. Now that they're behind me, I'm very happy, and I'm very excited to play my first match here."

Sane, who has played 70 times for the German national team, won four Bundesliga titles at Bayern after signing from Manchester City, with whom he lifted the Premier League twice.

He scored 13 goals in all competitions last season, helping Bayern win back the Bundesliga trophy from Bayer Leverkusen.