(Reuters) - Spanish infrastructure investment fund Asterion Industrial Partners and Telefonica agreed to sell Spanish data centre operator Nabiax to European asset manager Aermont Capital, the companies said on Monday in a joint statement.

Nabiax owns two centres in Madrid and one in Barcelona with a combined installed power of 35 Megawatts. Asterion owns 80% in Nabiax and Telefonica owns the remaining 20%.

The companies did not disclose the transaction's financial details, though people familiar with the matter told Reuters two weeks ago that Nabiax was worth around 1 billion euros ($1.07 billion).

The Artificial Intelligence boom has driven demand for data centres, leading to increased investment and deal activity.

Blackstone, Amazon and Microsoft have disclosed plans to invest several billion euros each in data centres in Spain.

Asterion formed Nabiax in 2019 through the acquisition of 11 data centres from Telefonica across Spain and Latin America. It sold its Latin American operations to British infrastructure fund Actis last year, with a view to focusing on its home market.

($1 = 0.9362 euros)

(Reporting by Joanna Jonczyk-Gwizdala, Editing by Inti Landauro and Barbara Lewis)