A U.S. trade negotiator today charged that Japan is stalling talks aimed at promoting larger sales of foreign radio equipment in Japan.

"They think things are fine just the way they are," said John J. McDonnell Jr., group vice president of the Washington-based Electronic Industries Association and an advisor to a U.S. delegation that completed two days of discussions here on Tuesday.

A Japanese official denied the allegations of delay, noting that opening positions are always far apart.

McDonnell's critical statement comes as Congress is considering legislation that would limit Japanese telecommunications sales in the United States unless Japan is perceived to have made its market as open as U.S. markets are to imports.

Prime Minister Yasuhiro Nakasone, who leaves later this month for a visit to New York and Washington, appears to be especially concerned that Japan create an image of good-faith negotiating.

A senior official at Japan's Ministry of Posts and Telecommunications tonight characterized the talks as being in preliminary stages. "We have only just arrived at specific talking points," he said. "This is just the starting position." He said Japan was prepared to continue meeting and to make changes in the law that governs the industry.

But McDonnell and another American involved in the talks, which have gone through four sessions since June, contend that no significant progress has been made.

The talks continue negotiations over the sales of telecommunications equipment that began here last year in an attempt to further open the Japanese market to foreign goods and to help defuse tension with Japan's foreign trading partners.

Until last spring, telephone equipment was at issue. U.S. officials later declared that most technical barriers to those sales had been removed. They are now working for similar concessions on radio equipment, a field in which they feel U.S. manufacturers are particularly competitive.

At issue this week were not simple consumer items such as transistor radios, but advanced telecommunications gear in which the United States is often far ahead of Japan in commercial applications -- car telephones, pocket pagers and radio-based data transmitters, for instance.

McDonnell estimated the market here for mobile equipment could eventually grow from the current $500 million or so a year to about $2 billion if the government would loosen regulations and approve new types of equipment for sale. He said U.S. companies might get 20 percent of those sales.

The U.S. complains that a wide variety of equipment that Japanese companies now sell in the United States -- pocket pagers that display lengthy messages rather than just beep, for instance -- cannot be sold in Japan because monopoly companies and the government have not approved them. They also say heavy regulation hampers sales.

In the talks this week, U.S. negotiators argued for an 11-point plan that provides for radical changes in regulations that govern radio-equipment certification, licensing of radio transmitters and allocation of radio frequencies.

Repeating themes of last spring, the U.S. wants to simplify standards and scrap rules under which Japanese officials must inspect individual pieces of equipment. Companies should be able to certify themselves that they are meeting the standards, the U.S. contends.

It also wants more say for foreign companies in drafting radio regulations and the removal of Japanese companies that are involved in the radio industry from a semi-official body here that inspects and approves equipment for sale.

Japanese officials argue that, by tradition, government here holds a tighter rein on regulations to give greater protection to the consumer.