Gold has edged lower, retreating further from last week's 3-1/2-month high as the US dollar regained some ground against the buoyant euro and traders bet on further US interest rate hikes after Friday's payrolls data. The dollar, which has remained weak after its biggest annual drop since 2003, had helped to lift assets priced in the US currency, with gold last week registering a fourth straight weekly gain for the first time since April.