TOKYO, JAN. 5 -- A top U.S. trade representative has been discussing U.S. concerns about Japan's semiconductor marketing and other trade issues with Japanese officials in informal talks, officials said today.

Michael Smith, U.S. deputy trade representative, exchanged opinions on semiconductors with the ministry's vice minister, Makoto Kuroda, for about an hour Monday, said ministry spokesman Makoto Yokota.

Japan has come under strong pressure from major trading partners to open its markets wider to foreign products and take measures to encourage the Japanese to buy more foreign and Japanese goods, reducing Japan's dependence on exports.

The United States in particular has been critical of what it sees as barriers to foreign products in Japan. In 1986, Japanese sales in the United States exceeded U.S. sales here by $58.6 billion, up from $49.7 billion in 1985.

In a related development, Japanese business leaders called today for greater efforts to deregulate Japan's market and stimulate local demand to help reduce the trade surpluses.

The heads of four main economic organizations also called on the Japanese government to address the problems of the high yen, taxes and spiraling land prices in 1988.

"The domestic market has to be fully opened," said Eishiro Saito, chairman of the powerful Keidanren, or Japanese Federation of Economic Organizations.

Yokota said another meeting scheduled Wednesday between U.S. and Japanese officials probably would deal with U.S. criticism of Japanese companies that keep the prices of their products low in the American market despite the sharp rise of the yen against the dollar. Smith was not here for official negotiations, and there was no definite agenda for his talks, Yokota said.

The dollar has been declining for three years, which theoretically helps reduce the giant U.S. trade deficit by making American goods cheaper abroad and foreign goods more expensive. U.S. officials have charged, however, that Japanese companies have been accepting lower prices in the United States in an effort to maintain their market share.

The United States also has objected to Japan's semiconductor marketing policies, which the Americans claim violated a 1986 trade pact. President Reagan slapped $300 million in tariffs on Japanese televisions, power tools and small computers last April in response.

A total of $135 million in tariffs were lifted after the Commerce Department reported that Japanese chip manufacturers had stopped selling chips below fair market prices, a tactic commonly called dumping.

Noboru Takeshita, who succeeded Yasuhiro Nakasone as Japanese prime minister in November, is to leave next Tuesday for visits to the United States and Canada, and trade issues will be a major topic.

Speaking to reporters after a New Year's party attended by nearly 2,000 people from business and trade circles, Takashi Ishihara, president of the Japan Committee for Economic Development, said a major task facing the government in 1988 will be to bring stability to the volatile foreign exchange market.

The Japanese yen has nearly doubled in value against the U.S. dollar since September 1985, when $1 bought 242 yen.

The high yen has hit Japan's export-oriented companies hardest, making their products more expensive abroad. Many companies have suffered sharp drops in profits and reduced their work forces.

"It is about time the U.S. thought of what to do with the dollar," said Ishihara.

Japan maintains that a major factor behind the weak dollar is the giant U.S. federal budget deficit.