Berta negotiated the sale of players including Antoine Griezmann, Matheus Cunha and Rodri, while £180m was spent in the 2024 summer transfer window on Julian Alvarez, Conor Gallagher, Robin Le Normand and Alexander Sorloth.
Atletico are currently third in La Liga and very much in the title mix. Berta came close to joining Paris Saint-Germain as Sporting Director in 2017 but opted to stay in Madrid.
Arsenal considered a number of candidates for the role and the process was driven by Managing Director Richard Garlick and Executive Vice-Chair Tim Lewis, with Co-Chairman Josh Kroenke and Manager Mikel Arteta also involved.
Assistant Sporting Director Jason Ayto had been doing the main job on an interim basis following Edu’s exit and was one of the candidates to replace him.