A statement issued by the Arianespace company, based near Paris, said the delay had occurred because the client responsible for one of the two satellites aboard the craft had needed to make some last-minute checks.

The launch had been due to take place at between 2249 and 2330 GMT from the ESA's space centre in Kourou, French Guiana. It was not known when the launch would now take place.

It was to have been the first launch of an Ariane 5 since December 12, when a beefed-up version of the rocket, an Ariane 5-ECA, suddenly veered off course on its maiden flight and had to be destroyed.

The failure, which was reckoned to have cost half a billion dollars, was a major setback for Europe's commercial satellite launch industry.

The rocket was to have carried two telecommunications satellites, the 2.95-tonne INSAT 3A for the Indian Space Research Organisation (ISRO) and the 1.76-tonne Galaxy XII for the US telecoms operator PanAmSat, into geostationary orbit.

It was not known which of the two was responsible for the delay. Arianespace officials said more details would be released on Wednesday.

SPACE.WIRE