TOKYO, JAN. 11 -- The government, worried that anti-Japanese sentiment might be aroused at a time when the U.S. economy is slumping, said today that it will continue for another year its policy of voluntarily restricting auto exports to the United States.

The move will have little economic impact because Japanese auto exports have been running well below the 2.3 million cars-per-year ceiling. An increasing share of the Japanese-brand cars sold in the United States now are made in the United States rather than in Japan.

But the 10-year-old export lid has become a politically important symbol and today's announcement comes at a time when many Japanese are worried that the recession may make the United States especially ripe for a protectionist backlash.

In Washington, five U.S. congressmen headed by House Majority Leader Richard A. Gephardt (D-Mo.) called Japan's decision to just extend the limits on auto exports "deeply disturbing" and said that any limits on shipments of cars to the United States should be accompanied by increased Japanese purchases of U.S. products.

Chrysler Corp. Chairman Lee A. Iacocca attacked the Japanese restraints as "another meaningless gesture." He said Japan should agree to a limit its total market share of cars imported into the United States as well as those made in this country.

By maintaining the export lid for the year starting April 1, Tokyo hopes to avoid being seen as exacerbating the already grim situation facing the U.S. auto industry, which has been shuttering factories and laying off thousands of workers in recent months.

The move apparently won't satisfy the United Auto Workers, whose president, Owen Bieber, urged Tokyo to set a limit on the Japanese automakers' share of the U.S. auto market rather than simply limiting exports. Bieber made his views known in a letter to Eiichi Nakao, the minister of international trade and industry.

A plan such as that endorsed by Bieber presumably would threaten at least some jobs held by U.S. workers at Japanese auto plants. But those jobs would probably not be UAW jobs, because the union has had little success in organizing the labor force at the Japanese "transplants."

Ford Motor Co. Chairman Harold A. Poling, meanwhile, called for discussions with Japan to reduce all its exports to the United States over the next five years. He said he favors a reduction of 20 percent to 25 percent from current levels.

Japanese vehicle exports to the United States fell below 2.0 million in fiscal 1989, well below the 2.3 million-unit ceiling, and they are expected to dip to around 1.8 million in the fiscal year that ends March 31.