The Japanese government today announced a new series of steps to open the market here to more foreign products, although senior officials acknowledged that the move will not bring any substantial reduction in Japan's huge trade surplus with the United States.

Adopted at a special meeting of key economic cabinet ministers, the measures are designed to cut through the web of legal red tape and complicated customs, product standards and testing practices that American business people complain keep them from successfully marketing products in Japan.

The broad package calls for rewriting 17 out of 32 stringent consumer safety laws now governing a wide range of goods, including pharmaceuticals, processed foods and electrical appliances. The revised government codes are expected to go into effect following approval by the parliament sometime later this year.

In Washington, U.S Trade Representative William E. Brock expressed optimism that the Japanese government's action, if approved by the parliament, will open new markets in Japan for American products.

"I am hopeful that, as a result of the review by the interministerial committee, 17 major Japanese standards and certification laws will be amended during this sesson of the Diet," Brock said.

He said the U.S. government "wholeheartedly supports" efforts by Prime Minister Yasuhiro Nakasone to win quick legislative approval of the new rules.

Today's action followed a comprehensive review of Japan's import proceedures which was ordered by Nakasone in January. Nakasone ordered the review in a bid to ease escalating economic tensions with the United States.

In the wake of a massive $19 billion U.S. deficit in trade with Japan last year, U.S. officials have warned that Japan's failure to act quickly to open its tightly closed market to more imports could touch off a protectionist backlash on Capitol Hill.

A senior Japanese official said the new trade package is intended to end a double standard here that, in effect, has forced foreigners seeking to sell products in Japan to meet more cumbersome, time-consuming and costly requirements than their Japanese rivals.

The official, who did not want to be named, said the measures formed "a very important pillar" of Japan's market-opening efforts and indicated that Tokyo would not adopt any other "sweeping" package of trade concessions in the foreseeable future.

In December, the Nakasone Cabinet decided to reduce import duties on a basket of 47 farm commodities and 28 industrial items and expand import quotas for a half dozen agricultural items, effective April 1.

As part of the new trade package, Tokyo pledged to streamline what are viewed in the United States as nit-picking customs inspection procedures and to reduce voluminous paperwork that often has caused lengthy dockside delay for the bulk of imported consumer goods.

For example, foreign automakers now will be allowed to get blanket clearance for all cars of the same make and model after having submitted only one vehicle for "type" inspection. Under the old system, a shipment could be held up for as long as seven months as customs officials methodically checked each car.

The Japanese government also decided to:

Accept, in principle, the results of product safety tests conducted in foreign laboratories in licensing imports of processed foods, automobiles and household appliances, among other items. Previously, importers have been obliged to submit products already meeting Japanese specifications to rigorous examination by local testers.

Speed up efforts to bring Japanese product standards more in line with internationally accepted standards, including those for automobiles, food additives and plywood.

Make available a complete list of Japanese standards, which have often been confidential in the past, and solicit views of foreign business people before drafting new codes.

Taken together, however, these measures were not likely to satisfy American trade officials. These officials have pressed for more dramatic action, including the full decontrol of beef and citrus fruit sales in Japan and expanded access to the market for telecommunications equipment.