DETROIT, June 2 (Reuters) - General Motors Co Chief Executive Mary Barra had a message on Friday for investors and rivals who see no profitable future in autonomous vehicles: You're wrong.

Barra told attendees at a Sanford Bernstein conference that she sees a "giant growth opportunity" in GM's Cruise autonomous vehicle unit, and predicted personal self-driving cars would be on the market before the end of the decade.

Barra reiterated a forecast that Cruise could generate $50 billion a year in annual revenue by 2030. GM currently is losing money on Cruise at the rate of $2 billion a year. Rivals, including Ford Motor Co and Volkswagen AG, have pulled the plug on autonomous vehicle efforts as losses mounted.

(Reporting By Joe White)