Alexandre Vinokourov and Andreas Kloeden will ride in this year's Tour de France after their Astana team received a wildcard into the race.
Astana are backed by a group of Kazakh companies
Vinokourov was one of last year's favourites but Astana had to withdraw after several of the team were implicated in a doping scandal.
The Kazakh rider was not involved himself but was left without enough team-mates to compete.
Kloeden was third last year while racing for the T-Mobile team.
Vinokourov is the reigning Tour of Spain champion and finished third in the Tour de France in 2003 and fifth in 2005.
The Agritubel and Barloworld teams have also been given wildcards to join 18 others in this year's race, which begins in London on 7 July.
British-registered South African team Barloword and Swiss-registered Agritubel are the only teams not taken from the Pro Tour series.
It means that Swedish-registered Unibet will be the only Pro Tour team not involved.
The internet betting company has fallen victim to a dispute between the major race organisers and the International Cycling Union (UCI) this season, because of the strict laws in France and Belgium against advertising betting companies.
Full Tour de France line-up:
Predictor-Lotto, Quick Step (Belgium)
AG2R, Agritubel, Bouygues Telecom, Cofidis, Credit Agricole, Francaise des Jeux (France)
Gerolsteiner, T-Mobile (Germany)
Barloworld (Great Britain)
Lampre, Liquigas, Milram (Italy)
Caisse d'Epargne, Euskaltel, Saunier Duval (Spain)
Discovery Channel (USA)