"The contract hasn't been signed yet, but discussions are under way and will most likely reach a positive conclusion," said Alain Fournier-Sicre, the agency's top representative in Moscow. "Pedro Duque is well qualified for the mission."

Duque studied aeronautical engineering at the Universidad Politecnica in his home town, Madrid, where he built flight simulators.

A keen diver, cyclist and Russian-speaker, he was selected for astronaut training in 1992.

The ISS mission would be the second journey into space for the 39-year-old, who completed a 10-day mission aboard a US space shuttle in 1998.

Duque would be the fourth non-Russian to travel to the ISS aboard a Soyuz rocket, following in the footsteps of Frenchwoman Claudie Haignere in 2001, Italian Roberto Vittori last year and Belgian Frank de Winne -- who is due to join a mission to the space station later this year.

Mission dates are likely to be confirmed only after the conclusion of an investigation into last week's explosion of a Soyuz rocket in which at least one person was killed.

A further eight people were injured last Tuesday when the Soyuz-U rocket blew up shortly after blasting off from the Plessetsk space centre, destroying the Photon-M scientific satellite it was carrying.

SPACE.WIRE