Germany defender Jerome Boateng has agreed a five-year contract and will officially join Manchester City on July 1.
Boateng has completed the formalities of his £10million move from Bundesliga side Hamburg before heading off on World Cup duty in South Africa.
"This is a very good signing for Manchester City and I am pleased to bring Jerome to the club," City boss Roberto Mancini told the club's official website.
"He is a young player who is already of a very high quality, but I think he can continue to improve.
"He can play a number of positions in defence, which is important. He has proved his ability in Germany and I think he can be a very important player for Manchester City in the Premier League."
Boateng is the 21-year-old younger brother of Portsmouth midfielder Kevin-Prince.
The centre-half or full-back is the third player signed by City from Hamburg in recent seasons, following the previous acquisitions of Nigel de Jong and Vincent Kompany.
Speaking earlier in the week about meeting Mancini, Boateng revealed:"He came with two representatives to Hamburg and we chatted for one or two hours.
"He convinced me to make the transfer. He believes that I will definitely need a few months to get settled in once in England, but that he sees so much potential in me that he will improve me."