Barcelona have officially announced the signing of Antoine Griezmann from Atletico Madrid, with the French forward handed a five-year deal.

According to the statement from Barcelona, the 28-year-old whose new contract contains a buyout clause of 800 million euros (£733m) is tied to Barca until June 30, 2024.

“With his arrival at FC Barcelona, the Frenchman takes another step forward in his career with the goal of consolidating his place as one of the best players in the world,” Barcelona said in a statement.

Griezmann had announced in May he would be leaving Atletico Madrid after spending five seasons in the Spanish capital.

However, as the world is coming to terms with what could be the third most expensive transfer ever, Atletico Madrid have confirmed they will institute legal action on Barcelona’s signing of Griezmann

The club claims they are entitled to another additional €80m over the French player.

Atletico Madrid alleges that the signing of Griezmann by Barcelona had been done before the clause dropped to €120m from €200 million, and that they are now thus entitled to a further €80m from Barca.

“Atlético de Madrid believes that the amount deposited is insufficient to meet its rescission clause since it is obvious that the commitment of the player and that of Football Club Barcelona was closed before the aforementioned clause was reduced from €200m to €120m.

“It was also prior to the date on which the clause was modified the communication that the player made on May 14 announcing his disengagement from the club.

“Atlético de Madrid believes that the termination of the contract occurred before the end of last season due to events, acts and demonstrations carried out by the player and that is why he has already started the procedures he considered appropriate for the defence of his rights and interests legitimate.” the statement read.

The cost of Griezmann’s move to Barcelona is believed to be only behind that of Neymar and Kylian Mbappe who moved from Barcelona and Monaco to PSG respectively.