"A fee of 19 million euros, payable in three separate instalments, has been agreed, with a potential extra two million euros to be added on if certain performance-related targets are met," said the Turin club.

Former VfL Wolfsburg and Bayern Munich forward Mandzukic scored 20 goals in 43 matches in all competitions for Diego Simeone's side last season as Atletico finished third in the defence of the title they won in 2014.

Juventus have already spent 32 million euros this month on signing Argentine forwardPaulo Dybala from fellow Serie A side Palermo. They join Carlos Tevez and Alvaro Moratawho formed a prolific striking partnership this season.

However, the signing of Mandzukic is another hint that 31-year-old Tevez, who has made it clear that he wants to finish his career at home with Boca Juniors, could be on his way back to Argentina with one year left on his contract.

Juventus, who won a Serie A and Coppa Italia double this season and reached the Champions League final, have already signed Germany midfielder Sami Khedira from Real Madrid to reinforce the midfield.

Khedira's move could facilitate the exit of France midfielder Paul Pogba, who is reportedly a target for clubs including Real, European champions Barcelona and several English teams as well as Paris St Germain.

It also remains uncertain whether 36-year-old playmaker Andrea Pirlo will stay for another season.