We present the results of the magnetization and dielectric constant measurements on untwinned single crystal samples of the frustrated S = 1/2 chain cuprate LiCu2O2. Novel magnetic phase transitions were observed. A spin flop transition of the spiral spin plane was observed for the field orientations H a, b. The second magnetic transition was observed at H ≈ 15 T for all three principal field directions. This high field magnetic phase is discussed as a collinear spin-modulated phase which is expected for an S=1/2 nearest-neighbor ferromagnetic and next-nearest-neighbor antiferromagnetic chain system.