NEW YORK, JAN. 5 -- Top General Motors Corp. officials said today that they will take advantage of increasing Japanese auto prices by cutting prices on a wide range of GM cars and trucks.

The company already has reduced prices of 127 of its car models by between $178 and $1,000, GM officials said. That is roughly 50 percent of GM's 1988 car fleet. The remainder of the cars carry higher price tags than last year, although GM says the increases average less than the 4.5 percent inflation rate.

More price cuts on "comparably equipped" vehicles -- 1988 models having features similar to those of their 1987 counterparts -- are possible this year, GM officials said.

Japanese auto prices have risen an estimated 26 percent since August 1985, or an average of $3,200 per car, said Christopher Cedergren, an auto industry analyst with J.D. Power and Associates in Westlake Village, Calif.

The Japanese are having trouble keeping the lid on their car prices largely because of costs generated by the rising yen and falling dollar.

By comparison, domestic auto prices have risen about 18 percent, or an average $2,200 per car during the same period, Cedergren said.

But even with the price hikes, the Japanese have increased their share of the U.S. auto market while GM has been losing ground. Now, however, buyers are beginning to show some resistance to the rising cost of Japanese autos, and that means opportunity for GM and other domestic car companies, Cedergren said.

"GM hasn't reduced prices in the past. But their backs are to the wall now," said Cedergren. "They need price rollbacks to help increase their market share," he said.

GM held 32.7 percent of the U.S. car market in December 1987, 5 percent less than it held in the same period in 1986.

But GM officials, here to celebrate what company Chairman Roger B. Smith called "the largest single show of technology and products in GM's history," said their decision to go with price rollbacks on comparably equipped cars and trucks was not born of desperation.

"The exchange rate is doing a tremendous favor for us by raising the cost of Japanese cars and, as a result, lowering their value," said Robert C. Stempel, GM president.

GM will continue its low-interest-rate loan and rebate programs, to which the company and its buyers have become addicted over the last eight years, company officials said.

Some auto analysts said today that GM's pricing action actually has increased prices for that segment of buyers looking for base-level cars, which have been replaced by models that carry formerly optional equipment as standard equipment and sell for higher prices. GM estimates that this market segment constituted about 10 percent of its buyers.

GM's increased product quality and production efficiency generated by its $50 billion investment in new plants and equipment since 1985 has also made it possible to cut prices on a number of models, Stempel said.

All of that investment "is finally beginning to pay off, for us and for the consumer," he said.

That, at least, is the message that the much-maligned auto giant is trying to get across here in its $20-million, three-day show-and-tell extravaganza, which ends Thursday.

The program, "Teamwork and Technology," is a throwback to GM's gala new-car introductions at the Waldorf-Astoria here, begun in 1932 and discontinued in the early 1960s.

This year's show is also at the Waldorf, where GM has invited 14,000 stockholders, dealers, securities analysts, bankers and journalists for a look at its current and future products, as well as examples of its aerospace and communications projects.

The idea is to rebuild the company's badly damaged image.

"People say that: 'Well, GM is big. It can take a lot of bashing.' But the GM-bashing over the last four years has hurt company morale, and it's hurt sales. We're trying to put an end to that," Stempel said.