French railway engineers made a costly blunder when they failed to realise that hundreds of new trains are too wide for many older stations.

Nearly 1,300 stations are just a few centimetres too narrow for the order of 341 trains, which were to be introduced between now and 2016.

Although they measured the new trains, and checked against the latest specs on the book, the engineers forgot to go and measure the actual distance between lines and platforms.

It will cost 50 million euro to fix the problem.

The problem with older stations was first reported in the French weekly Le Canard Enchaine and confirmed by French railway and government officials.

Jacques Rapoport, president of rail infrastructure organisation RFF, acknowledged the problem was "discovered a little late", but told Europe 1 radio that the cost would not be passed on to customers.