GM has been trying to sell the loss-making brand for the last year and signed a deal with Tengzhong in October. However, resistance from Chinese regulators, who have been putting the brakes on investment in the fast-growing Chinese auto industry, created difficulties from the start. GM said it will continue to honor existing Hummer warranties. It is now focusing its efforts on its four remaining brands: Chevrolet, GMC, Cadillac and Buick. __