Ferrovial, one of Spain’s biggest construction groups, was on Wednesday facing the threat of a forced sale of three of its British airports next year, after a damning report by UK competition authorities attacked its dominance of the industry.

The UK Competition Commission provisionally concluded that Ferrovial’s subsidiary, BAA, should be forced to sell two of its three London airports – Heathrow, Gatwick and Stansted – and either Glasgow or Edinburgh in Scotland. The most likely candidates for sale are Gatwick, Stansted and Glasgow, analysts said.