Train and bus operator Go Ahead has exchanged contracts to sell its airport ground handling and cargo operations to focus on its rail and bus activities.It is selling ground handling and cargo operations at Heathrow and Manchester Airport to Middle Eastern travel group Dnata for £15m. Most airport operations outside Heathrow are being sold to global aviation Servisair for a 'nominal' consideration.'This announcement marks another important step in delivering the Group's strategy which focuses on growing our core bus and rail operations,' Go-Ahead chief executive Keith Luderman said.The announcement does not affect the company's Meteor car parking businesses, which operate at several airports. Go-Ahead operates train services including the Gatwick Express between Gatwick Airport and London and the Southern Franchise, as well several local and regional bus operations.The company said that the transactions announced today are expected to be broadly cash neutral, with the £15m proceeds offset by costs such as future losses and residual liabilities. It will also incur an exceptional loss of £20m.