Airport operator BAA has agreed to sell Gatwick to a rival airport operator for £1.51 billion.

The acquisition of Britain’s second busiest airport is being made by Global Infrastructure Partners, which owns London City airport.

Of the sale price, £55 million is conditional on future traffic performance and the buyer’s future capital structure. Proceeds generated by the sale will be used to pay off part of BAA’s debt.

The sale must now receive EU merger regulation clearance and is expected to be completed in December.

BAA chief executive Colin Matthews said: “Gatwick and its people have long been a central part of BAA, and we are proud of the airport’s development as one of the world’s leading international airports.

“BAA is changing, and today’s announcement marks a new beginning for both Gatwick and BAA. We wish Gatwick well for the future and are confident that the airport will flourish under new ownership.

“BAA will focus on improving Heathrow and our other airports.”

The deal follows BAA’s announcement that it would sell Gatwick in September 2008 after the Competition Commission recommended BAA put two of its three airports up for sale. At the time it was thought the airport could be worth as much as £2 billion.

BAA has also been ordered to sell Stansted and either Glasgow or Edinburgh, but it is appealing against the decision.