According to Spanish newspaper Expansion, Spanish infrastructure group Ferrovial has offered Heathrow Airport Holdings (HAH) 800 million pounds ($1.3 billion) for British airports Aberdeen, Glasgow and Southampton.

The Spanish company holds a 25 percent stake in HAH, previously BAA, which is owned by a consortium including Britannia Airport Partners, Singapore's GIC, Qatar Holding, Universities Superannuation Scheme Limited (USS) and Alinda Capital Partners.

Global Infrastructure Partners (GIP) and other investors could be potentially interested in buying the assets. GIP currently owns Gatwick, London City and Edinburgh airports. Manchester Airports Group, which owns Stansted, would also be a likely bidder for some of the Heathrow-owned airports.

According to the source, Heathrow airport accounts for more than 95% of its parent company's annual profits, which would make the sale of the other regional assets "inevitable" within the next three years.

Ferrovial bought Heathrow, Britain's busiest airport, and a number of other UK airports as part of its acquisition of BAA in 2006 for 10.3 billion pounds.