Manchester City have completed the signing of Portuguese defender Ruben Dias from Benfica, the Premier League side said on Tuesday, as Argentine defender Nicolas Otamendi moved the other way as part of the deal.

City's statement said Portugal international Dias, 23, had signed a six-year deal with the club, without mentioning a transfer fee.

Benfica had said earlier on Tuesday that Dias had signed for 68 million euros ($79.83 million) plus 3.6 million in variables, while Benfica had agreed to pay 15 million for Otamendi.