In a bid to avert a protectionist backlash in the United States and Europe, Japan's ruling Liberal Democrats announced a series of steps to dismantle the country's trade barriers and open its markets to more foreign products.

The government party's proposal, which is expected to be adopted formally by Prime Minister Zenko Suzuki's cabinet on Jan. 30, calls for the immediate easing or elimination of 67 so-called nontariff trade barriers compiled from a list of 99 specific complaints registered by major trading partners.

The proposed changes deal mainly with what foreign trade officials view as overly stringent customs, product standards and testing requirements for a broad range of items, including cosmetics, pharmaceuticals, processed foods and sporting goods.

Few observers here, however, expect these measures to reduce significantly the huge and sharply rising surpluses that Japan has piled up on trade with the United States and Western Europe. The trade package is almost certain to fall far short of U.S. expectations. U.S. officials have asked Japan to undertake more sweeping changes in its web of rules governing imports, particularly those concerning high-technology products such as data-processing and telecommunications equipment.

But these actions reflect the mounting concern in government and political circles here over escalating demands by Reagan administration trade officials and their European counterparts that Japan move quickly to open its markets to more imports or face protectionist action.

In Washington, Commerce Secretary Malcolm Baldrige said today he personally would favor retaliatory action against Japan if it did not open more markets to U.S. imports.

Baldrige said the U.S. trade deficit with Japan could grow to between $18 billion and $20 billion this year. "It will be impossible for Japan to continually export more without importing more," Baldrige told a news briefing that was held just before the Liberal Democrats were announcing their trade measures. "I really hope that Japan responds to this problem," he said. "I think they will."

The Cabinet officer warned that if Japan doesn't act, he would support legislation now under consideration in Congress to impose so-called reciprocity trade penalties against Japan in such areas as telecommunications equipment and computer products and services. He did not set a deadline.

Baldrige was unavailable for comment following the Tokyo announcement.

During an interview in his Tokyo office today, Masumi Esaki, who heads a government party task force set up to deal with thorny trade issues, said "these measures in themselves will not completely solve the trade problem. We must do more."

But Esaki, a former minister of International Trade and Industry and veteran economic troubleshooter, suggested that part of the problem lies with foreign businessmen who, in the Japanese view, have not made vigorous enough efforts in the past to market their products here.

The ad hoc committee was set up late last year on the direct orders of Prime Minister Suzuki, and its proposals are part of a larger government effort to show Japan's good faith in dealing with trade complaints, including plans to speed up tariff reductions on some 1,600 items agreed upon under the Tokyo Round of multilateral trade negotiations.

Meanwhile, Esaki's task force has decided not to act on 23 outstanding nontariff-barrier issues despite strong U.S. and European demands.