The confirmation was made two weeks after the Portuguese club had confirmed his sale and almost a month after Jackson Martinez himself had said he was moving to Spain
Jackson Martinez will replace Mario Mandzukic who has moved from Spain to Juventus in Italy for 19 million euros. Martinez has been the top scorer in Portugal for the last three seasons.
Luiz Henrique Pompeo said that Atletico are prepared to pay Martinez's 35 million euros buy out clause.
Former titleholders Porto made it three out of three with a pulsating 3-2 Champions League win over Dynamo Kiev to maintain possession of Group A here on Wednesday.