A company set to be 80% owned by Spain’s wealthy Sanahuja family has completed the acquisition of HSBC’s Canary Wharf headquarters.

This morning Metrovacesa confirmed that it would buy the building for £1.09bn, the largest single property deal in UK history, and lease it back to HSBC for 20 years at an annual rent of £43.5m with an option to extend for a further five years.

The acquisition of the HSBC tower by the Sanahuja family’s Cresa Patrimonial arm was revealed by Property Week on Friday.

Metrovacesa also announced that there would be a spin off of the company in the near future, the result of which will be Cresa controlling around 80% of the company, representing nearly €10bn worth of assets.

This transaction will be completed within the next few months, with Joaquin Rivero, executive chairman, and his supporters taking control of the mainly commercial stock in France.

Metrovacesa has taken a 998-year lease on the building, in which HSBC will retain full control of occupancy.

David Hodgkinson, group chief operating officer of HSBC, said: ‘This is a good opportunity for HSBC to manage its property assets effectively and we're pleased to do so with the assistance of Metrovacesa, one of Europe's pre-eminent property companies.’

Jesus Garcia de Ponga, deputy to the chairman of Metrovacesa, said: ‘The acquisition of the HSBC global headquarters through this sale and leaseback transaction is evidence of our commitment to establish a significant presence in major international cities such as London and thereby achieve our aim to be one of the world's leading international real estate investors.’

The deal is expected to complete in the first half of 2007. CB Richard Ellis acted for HSBC, and Colliers International and Colliers CRE acted for Metrovacesa.