American Motors Corp. Chairman Gerald Meyers forecast yesterday that world automobile manufacturing ownership will become even more concentrated over the next two decades.

He also indicated his belief that AMC and the troubled Chrysler Corp. will be among the survivors in the year 2000, when there may be but a dozen independent car manufacturers worldwide compared with 30 today.

In an address to the National Press Club, Meyers noted that this is the same track followed in the domestic industry, which has shrunk from more than 100 manufacturers in 1920 to just four firms today.

The third largest of those firms, Chrysler, recently replaced American Motors as the weakest U.S. car maker financially. But Meyers forecast a long life for competitor Chrysler and also said he expects to stay in his job for the next 15 years, by which time he will be 65 years old and ready for retirement.

Meyers came to Washington yesterday for a very rare AMC public presentation to reporters other than traditional new-car showings. He told a story of how the nation's smallest auto firm was able to survive the turbulent 1970s -- an ear of gasoline scares, recessions, new regulations. He also carried a message of optimism about the coming decade.

But Meyers couldn't escape questions about his large, ailing competitor, nor the obvious suggestion that AMC survived a rough period while Chrysler had asked for $1.2 billion of federal loan guarantees to keep its business from failing.

Meyers is an industry veteran, however. Like his colleagues in Detroit and in most corporate board rooms, he didn't want to answer the question on every reporter's

"Is it wise . . . to bail out Chrysler because of its bad management?" he was asked.

"In principle, I believe -- and we believe -- that the government should not intrude into the marketplace . . . at almost any cost," he replied.

However, he continued, the "any cost" caveat may apply to Chrysler, and it would be wrong for "social" reasons to reject federal aid. "Practical considerations" about the hundreds of thousands of jobs involved raise "important people considerations and social considerations," said Meyers, who began his industry career in 1950 with Ford Motor Co., later worked for Chrysler and joined AMC in 1962.

Told that he hadn't answered the question, Meyers said he would "try again," but he offered a similar response. He declined to propose any solutions to Chrysler's plight, stating that other persons with more expertise are at work on the issue.

At the same time, Meyers noted that Chrysler is a customer and supplier of AMC, and that "whatever happens, we wish them well." Later he emphasized his conclusion that Chrysler will be kept alive. "Chrysler's going to make it; we have no feeling to the contrary," Meyers said when asked if AMC had other sources for such components as automatic transmissions that it now buys from Chrysler.

Moreover, future demands on the world auto industry will require more use of common parts by various manufacturers and more international joint ventures, Meyers told the Press Club.

AMC's own recent affiliation with Renault of France is an example of worldwide industry trends and one he forecast will give the U.S. firm "a respectable share of the total market as time goes on."

Focusing on AMC's recent turn-around, Meyers revealed that sales of his company will exceed $3 billion in the fiscal year ending this month compared with $2.6 billion a year ago. In the first nine months of the current year, AMC earned more than $80 million in pretax profits compared with $40 million in all of the previous fiscal period, "and we're not done yet," said Meyers, AMC's chief executive since 1977.

"Rather than slugging it out head to head across the board with the bigger automobile companies, we are concentrating only on those segments of the market where we see high promise: our specialty and Jeep vehicles, our small-car lines, four-wheel-drive Eagle line [a 1980 model introduced last week] and, eventually, other entries," said the AMC chief in discussing how his firm "is making it."

Meyers forecast that consumers will triple their investments in cars over the next two decades, with 180 million Americans of car-buying ages in 1985 compared with 160 million today. Next year, two-thirds of young new-car buyers will select small cars and, by 1985, 80 percent will do so, he predicted.

The net result is that Americans will buy 50 million small cars in the next five years compared with 27 million in the last five years, and that's why AMC is "so optimistic about the period ahead," he said.

As for the impact of government regulations, cited most often by Chrysler executives as the reason for their company's current plight, Meyers said "I am not coming to Washington and telling you that government regulations are welcome. They're not. Nor do we say they are putting us out of business -- yet. They are onerous and they're costly."

On other topics, Meyers said:

Worldwide, auto firms are planning to invest "a staggering $110 billion" between now and 1990 on the assumption that car and truck demand will keep growing. In the past decade, U.S. firms alone sold 125 million vehicles.

All new AMC cars are being built "so that they will not rust through under the worst conditions for at least five years," and the company offers a guarantee to consumers to repair any rust damage.

Renaults will be produced at AMC's plant in Kenosha, Wisc., within "a couple of years" as part of the new association with the French firm, which opened up the doors of AMC dealerships to market Renaults. A specific U.S.-built Renault model hasn't been selected, he said.