Borussia Dortmund has unveiled the signing of Jude Bellingham from Birmingham in a £25million deal. The English footballer, who plays as a midfielder has now become the world's most expensive 17-year-old, following his deal to the German club. It is believed Bellingham will earn £52,000 a week after penning the bumper contract which will likely see his former club earn in excess of £30m should certain performance targets be met. The Bundesliga giants confirmed the capture in a social media post that shows several players welcoming the new addition by signing along to the famous Beatles hit Hey Jude. Dortmund sporting director, Michael Zorc, has expressed his delight with the signing, saying: 'Jude Bellingham has decided with absolute confidence to pursue his career at Borussia Dortmund. The primary motivation behind his decision were the prospects on the pitch we were able to offer him. 'He has enormous potential, which we will continue to develop together with him over the coming years. He already boasts astonishing quality with and without the ball and has a strong mentality to boot. 'Jude will immediately strengthen our first-team squad, but we will certainly give him all the time he needs to adapt to the higher level of play.' In a statement, Bellingham revealed his excitement after joining the Bundesliga club and thanked his former club where he kicked off his career. 'I can’t thank Birmingham City enough for what they have done for me, not just this season, but since the age of seven,' he said. 'Of course, I wish everyone associated with the club nothing but the best. Once a blue, always a blue. However, I’m incredibly excited to have joined one of the biggest clubs in Europe. 'The direction they are heading in and how much they help young players improve made its fans when they are back inside one of the most beautiful stadiums in the world – hopefully as an easy decision for me personally and my family. I can’t wait to perform in front of over 80,000 as soon as possible!'