A conjecture of Colliot-Thelene in the case of the exceptional groups We consider a regular local ring R containing an infinite field of characteristic different from 2, the fraction field K of R and a simple algebraic group scheme G over R. The question is whether for a given parabolic subgroup in the group G_K there is a parabolic subgroup scheme of the same type in G over R. We answer the question in the affirmative provided that G has type G2, F4, or E6. If G is of type E7 or E8, then we answer the question in the affirmative for most types of parabolics. This partly solves a conjecture of Colliot-Thlne and extends an earlier result of I. Panin and K. Pimenov for quadratic spaces.