Borussia Dortmund have confirmed that club captain Mats Hummels will join rivals Bayern Munich this summer on a five-year deal.

The Bundesliga champions are reported to have agreed a fee of 35 million euros ($39.81m) with Dortmund and confirmation of the move comes two weeks after the club had announced that Hummels wanted to leave for Bayern. The German World Cup winner's contract with Dortmund was due to expire in 2017.

Hummels' transfer came hot on the heels of Bayern's multi-million euro deal for Benfica's teenage sensation, Renato Sanches, whose signing was also confirmed on Tuesday.

"After so many successful years at Dortmund, it wasn’t an easy decision," Hummels explained in a press release. "I am and always have been proud to wear the Dortmund shirt and to be part of this extraordinary side.

"Before I return to my hometown in the summer, we still have one big, common goal: to bring the German Cup back to Dortmund and celebrate with BVB fans," he said.

"From the bottom of my heart, I want to thank my teammates, all the staff and the fans for this long and wonderful time in black and yellow."

In signing for Bayern, Hummels returns to the club where he spent his youth career. Hummels made two appearances for the Bayern first team before joining Dortmund in 2008 (initially on loan) and signing permanently in 2009.

Bayern's CEO Karl-Heinz Rummenigge said the club is thrilled to have Hummels back.

"We are delighted that Mats has decided in favor of Bayern," commented Rummenigge. "Mats is one of the best centre-backs in the world. With him we will increase the quality in our team even further."

The controversial move had been expected since Dortmund were forced to reveal Hummels' intentions earlier this month. An announcement had to be made because of Dortmund's position on the stock market, with share prices fluctuating depending on major news.

After the move was confirmed, Dortmund CEO Hans-Joachim Watzke said Hummels had handled the situation well.

"Mats has decided after long, intense reflections to return to his native Munich eight and a half years after his move to BVB," he said. "I want to emphasize that he has at all times behaved openly and fairly towards us.

27-year-old Hummels made 307 appearances for Dortmund, scoring 25 goals. He won two Bundesliga titles and a German cup while at Dortmund as well as playing a major part in Germany's World Cup win in 2014.