The Space Adventures company said it had reached an agreement with the Japanese advertising giant Dentsu to sponsor the mystery guest on a mission to the ISS on a Russian Soyuz rocket.

"Together we will make history by sending the first Japanese explorer to space," said Space Adventures president Eric Anderson.

He said the mission would happen in the next few years.

Space Adventures, based in Arlington, Virginia, said it has a deal with the Russian federal space agency guaranteeing four places on Soyuz missions.

The first place has already been bought by American technology entrepreneur Greg Olsen, who is training in Russia for a space trip scheduled for April 2005. Olsen is believed to have paid about 20 million dollars.

The Japanese will be the second and two other seats remain.

Space Adventures also organised the first space trips for paying customers: American businessman Dennis Tito in 2001 and South African Mark Shuttleworth in 2002. They also went on Russian rockets.

SPACE.WIRE