A lubricating oil circuit of a turbomachine includes a distribution valve that distributes an oil flow rate among a first heat exchanger and a bypass duct, connected to an oil duct, which is connected to an heat exchanger positioned against a turbomachine fuel passage duct, and includes a gearbox of a rotation speed reducer that lowers a rotational speed of a first rotary fan shaft of the turbomachine relative to a rotational speed of a second low-pressure compressor rotary shaft of the turbomachine or of a second low-pressure turbine rotary shaft of the turbomachine, and a regulation device. The regulation device includes a local regulation loop that generates an oil flow rate distribution control signal and regulates an oil temperature of the oil duct on a temperature setpoint, and a global regulation loop that generates the temperature setpoint as a function of the temperature and of the temperature setpoint.