Porto have signed Netherlands international Bruno Martins Indi from Feyenoord for an undisclosed fee, the Portuguese club have announced.
The 22-year-old centre-back, who featured in six World Cup games as the Oranje reached the semifinals and won the third-place playoff, has signed a four-year contract at the Estadio do Dragao.
Martins Indi had reportedly been a target for Louis van Gaal, the outgoing Oranje coach who officially took charge of Manchester United on Wednesday.
Speaking through Feyenoord's official Twitter account, Martins Indi said: "I've always said that if I left the club then it would be to make a step up.
"As well as saying a special 'thank you' to my teammates, I would like to thank the Feyenoord fans for their unconditional support."
A further tweet from the Rotterdam club read: "After many years at Feyenoord we would like to wish Bruno every success with Porto and in his future career."
The left-footed Martins Indi graduated from the youth academy at De Kuip to make 102 Eredivisie appearances for Feyenoord, and has has so far earned 22 senior caps for the Netherlands having made his international debut in 2012.