The 37-year-old, who returned to the saddle this year to promote the efforts of his Livestrong Foundation and their fight against cancer, is to quit Astana after just one season.
Armstrong, who won the Tour every year between 1999 and 2005, is third in the general classification in this year’s edition heading into the final three days.
Armstrong said in the statement: “To be able to compete for an American team comprised of the world’s top cyclists, supported by the best coaches and staff — I couldn’t be happier to partner with RadioShack.”
Lee Applbaum, RadioShack’s chief marketing officer, said: “As one of the greatest athletes of our generation, a father, a cancer survivor, and a tireless advocate in the fight against cancer, Lance Armstrong understands the power of keeping people connected and that’s why we feel he’s the perfect partner for our brand.”
RadioShack is a consumer electronics retailer.