A hydraulic control system in a continuously variable transmission (2) is provided with a pump (40) for supplying hydraulic fluid, a main line (41), a line pressure valve (V3), an auxiliary line (42) and a auxiliary pressure valve (V9). The line pressure valve (V3) being arranged to control a line pressure LP in the main line (41) by discharging a surplus of hydraulic fluid supplied by the pump (40) into the auxiliary line (42). The auxiliary pressure valve (V9) is arranged to variably control auxiliary pressure AP in the auxiliary line (41), preferably in dependence on the line pressure LP in the main line (41).