The Japanese branch of American Home Assurance Company on Sept. 2 begins mail-order sales of differentiated-rate auto insurance, the first of its kind in Japan.

The U.S. firm is able to sell the insurance because the Finance Ministry lifted a ban on differentiated-rate products in August, following a Japan-U.S. insurance accord in December.

American Home's announcement heralds a new age of rate competition in the auto insurance industry, though it is expected that domestic firms will remain bound by restrictions until next July. While domestic rivals admit there is an advantage in offering low premiums for good drivers, they doubt that the new service can offer much quality, considering the scarcity of American Home's service centers across the country.