The deal was part of a larger arrangement that also envisages Malaysia buying Russian Su-30 MKM fighter jets, officials from Russia's state-controlled arms export agency, Rosoboronexport, said.
Under the arrangement, two Malaysians will be chosen from a group that includes two doctors, one pilot and one engineer to prepare for the flight at Russia's cosmonaut-training facilities. Russian space officials said the flight was planned for September 2007.
The ITAR-Tass news agency said the entire deal would be worth about US$1 billion (Ђ780 million).
In recent years, Russia's space agency has complemented scarce state funding with revenues from commercial flights for space tourists and has courted other nations looking to send their citizens into space.
This spring, a Brazilian astronaut became the Latin American's country's first man in space, the AP reports.
Russian spacecraft have also served as the only links with the orbiting station since the U.S. space shuttle fleet was grounded following the 2004 Columbia disaster.