BVB have granted the Germany international's wish to join Bayer after the defender spent eight years at Signal Iduna Park
Sven Bender will join twin brother Lars at Bayer Leverkusen, Borussia Dortmund have confirmed, in a deal reported to be worth around €15 million.
Bender – whose switch is subject to a medical – joined Dortmund from 1860 Munich in 2009 and made 224 appearances for the club, winning the Bundesliga and DFB-Pokal twice.
The 28-year-old has been capped seven times by Germany and will move to Leverkusen in a deal worth a reported €15million.
Fitness problems including torn ankle ligaments hindered Bender last season, restricting him to three Bundesliga starts, and he told Dortmund chief executive Hans-Joachim Watzke and sporting director Michael Zorc he felt the time was right for a fresh challenge.
"A few days ago, I approached Aki Watzke and Michael Zorc with a personal request to take a new challenge after eight years at BVB," he told Dortmund's official website.
"As a little boy, I always wanted to be on the pitch. Also due to injuries, I have unfortunately unfortunately not been able to be used by BVB regularly.
"I am very grateful that Borussia Dortmund has respected my will, despite their unconditional desire to keep me. I feel that as a great appreciation."
Watzke added: "We would have liked to see Sven Bender still in our team. On the other hand, he is a player who, like a few others with great achievements, has given a lot of himself to BVB.
"These merits naturally require us to listen more closely and respect his personal desire."
Leverkusen begin their domestic season with a trip to Karlsruhe in the DFB-Pokal before opening the Bundesliga campaign away to reigning champions Bayern Munich.
Bender's first reunion with Dortmund will come in December when Peter Bosz's side travel to the BayArena.