UK-Spain dispute over Gibraltar threatens European skies reform

A police officer watches as a British Airways aircraft takes off from Gibraltar International airport in front of the rock of the British Colony of Gibraltar, in Gibraltar, south of Spain August 4, 2013. REUTERS/Jon Nazca

BRUSSELS (Reuters) - The dispute between Britain and Spain over Gibraltar threatens to hold up European Union plans to merge national air corridors, diplomats say.

EU member states are trying to reach agreement on the Single European Sky scheme, intended to complete the integration of some of the world's most crowded airways, cutting costs and CO2 emissions.