S.L. Woronowicz proved in 1991 that quantum SU(1,1) does not exist as a locally compact quantum group. Results by L.I. Korogodsky in 1994 and more recently by Woronowicz gave strong indications that the normalizer S̃U(1, 1) of SU(1, 1) in SL(2,C) is a much better quantization candidate than SU(1, 1) itself. In this paper we show that this is indeed the case by constructing S̃Uq(1, 1), a new examp...