Bus and train group Stagecoach today signalled its departure from airport management by selling Glasgow Prestwick International to a New Zealand investment firm for £33.4 million.

The deal spells the end of the company's three-year interest in airports, and means Perth-based Stagecoach can now concentrate on expanding its rail and bus divisions. In Hampshire it operates South West Trains and Hampshire Bus.

The airport's new owners are a consortium consisting of New Zealand investment firm Infratil, rival Special Utilities Investment Trust and Scottish-based local transport group Omniport.

The sale follows Stagecoach's decision to focus on its core rail and bus interests and to release cash to clear £7 million of debts.

The company paid £41 million for Prestwick in 1998, turning the loss-making business into Britain's busiest freight airport.

The deal means the end for the company's specially-created Stagecoach Aviation branch.