Reagan administration trade officials believe that Japan is conducting an orchestrated campaign of disinformation to provide a rationale for the failure of Japanese companies to honor a trade agreement to increase their purchases of U.S. semiconductors.

In late December, Japanese newspapers splashed a story over their front pages that the country's National Space Development Agency was postponing a launch because of defective U.S.-made semiconductors in the rocket.

That story has mushroomed over the past month into a broad-based Japanese attack on the quality of American-made semiconductors, causing administration trade officials to raise the issue in meetings with their Japanese counterparts.

Japanese officials here and in Tokyo have denied waging a campaign to attack American quality, and last week Japan's space agency backed off from implications that the launch postponement was attributable to a defect in a U.S.-made semiconductor.

Nonetheless, the attacks on the quality of American semiconductors persist in the Japanese press. In an editorial, for instance, The Japan Times pointed to the postponement of the rocket launch and stated, "One of the reasons that U.S. microchip producers have difficulties in selling here is that their semiconductors are perceived to contain more defects than Japanese chips."

"Quality is an easy thing to use as an excuse. Quality is no longer an issue, but it certainly serves as a pretext for not making purchases," said Alan Wolff, Washington counsel for the Semiconductor Industry Association.

Commerce Undersecretary Bruce Smart noted as "a strain running through the whole relationship" that "Japanese love to say that Americans can't do anything right."

The semiconductor involved in the space shot was made by National Semiconductor Inc. and bought by TRW Components International Inc., a U.S. company that has a contract with the Japanese space agency to supply voltage regulators used in the rocket. TRW reported that it fully tested the semiconductors as well as the voltage regulator and found they met all the specifications.

"If that is true, and it is being represented by Japan as being bad American quality, that's a bad rap," Smart said.

This issue is important because figures show that Japan is still not complying with provisions of a semiconductor trade agreement signed in September 1986, calling for it to increase its purchases of American semiconductors. Wolff said the intent of the pact is to have the U.S. share grow to 20 percent by 1991.

In fact, recent Japanese statistics showed that the market share of foreign-made semiconductors has decreased every month since June. Wolff said U.S. sales now amount to 10 percent of the Japanese market, instead of the 12 percent envisaged in the agreement. By the end of the year, the U.S. market share should be 14 percent, Wolff said.

President Reagan has retained $164 million of the $300 million in trade sanctions he slapped on Japan last April because it still has not fulfilled that part of the agreement calling for increased purchases of U.S. chips. Wolff indicated the industry might ask the president to increase those sanctions in an effort to force Japan to buy more semiconductors.

Japan's booming electronics and automotive industries now use half of all the semiconductors produced in the world, and U.S. high technology manufacturers have complained that being shut out of that market limits their ability to be internationally competitive in a wide range of products.

In reporting the postponement of the launch set for Feb. 1 until at least Feb. 16, the newspaper Mainichi Daily News quoted Japanese space agency spokesman Mikihisa Hagihar as blaming "flaws in special integrated circuits made by National Semiconductor of the United States" for the delay.

Nonetheless, TRW called the part "reliable for the intended space application." Under pressure from the U.S. companies, another space agency spokesman, Eijiro Hirohama, later described the launch delay as precautionary and said it was not due to a faulty U.S.-made part.