The recurring spasms of bankruptcies and bank failures are one overt sign of the upheaval in the economy today.

They are echoed by wrenching changes in some of the biggest, most richly endowed companies, such as American Telephone & Telegraph Co. and E. I. du Pont de Nemours & Co.

AT&T's consumer and business communications unit has announced it will eliminate more than 24,000 jobs in the coming months, in an effort to make the company more competitive in a cutthroat telecommunications equipment industry. AT&T's share of this market has plummeted from 50 percent in 1979, before the court-ordered breakup of the Bell System, to under 30 percent now, according to industry estimates.

The change at Du Pont has so far been less painful, but equally sweeping.

Du Pont's foundation is in chemicals, fibers and textiles, and until recently, it was a foundation that permitted strong, steady growth. The chemical business grew at about double the rate of the increase in the nation's gross national product in the 35 years following World War II.

But it is clear that that foundation no longer will support the company. Its textile and chemicals businesses are under withering pressures from imports, bolstered by the high level of the dollar. From mid-1984 until now, there has been no growth in the industrial sector, and Du Pont's business reflects this stagnation. Its sales and profits are down this year from last year's levels, and the cash flow from its businesses has slowed sharply.

This reality has forced Du Pont into its difficult mid-course correction. "We went into the '80s expecting more growth," said Du Pont Chairman Edward G. Jefferson. "That was wrong. We were organized for growth, and we had to slim down."

For Du Pont, that meant a 20 percent reduction in its work force, from 179,000 to 140,000 in the past four years.

And that reduction has been amplified tremendously by the change in direction at the company.

Du Pont has had to take one of the nation's biggest, best endowed and successful research institutions and spin it in its tracks, to turn toward the new directions Du Pont must follow to prosper in the 1980s and 1990s.

A research organization whose traditional strengths lay in chemical engineering and the sciences of plastics and fibers had to develop completely new kinds of expertise in the new fields Du Pont is aiming at -- in biotechnology, plant science, electronics and the diagnosis and treatment of disease.

And it had to do so within a few years without adding to the overall number of scientists and technicians on the payroll.

"It's a complex process," said Du Pont's Jefferson. "We identified the kinds of talents we needed, decided where those talents existed within the organization, and where there were people who could easily become proficient [in new scientific areas]."

The transition could not have been done without an unprecedented turnover in its research staff. It is a source of considerable pride to Jefferson that the shift was essentially accomplished not by layoffs and pink slips but through attrition and an early retirement program that has taken 11,200 employes off the payroll, three times the number that Du Pont had initially anticipated.

That gentle-handed approach to cost-cutting is in keeping with the culture at Du Pont, one of the most paternalistic, familial companies in the country.

But gentle or not, Du Pont had no choice. "The story at Du Pont is change," said Robert Reitzes, a Wall Street analyst who follows the company for Mabon Nugent. "The market is demanding change, and they recognize that."

It is hard to find an American company that is immune from the pressures that spring from a fiercely competitive global market and from an unprecedented rate of technological change.

Looked at in the broadest sense, on a national scale, the upheaval should be a plus for the economy and for companies and their employes, moving them to new anchorages where the prospects for growth and prosperity are stronger.

But the disruption is staggering in many cases.

"There are enormous dislocations in any given company situation," said Jefferson's predecessor as Du Pont's chairman, Irving S. Shapiro. "Managements are threatened and displaced. Plants are closed in communities. Workers are displaced. Economics becomes the driving force, and other considerations tend to be submerged and that's troublesome, because as important as economics is, it's not the only issue that one has to deal with.

"I quickly concede if you don't have earnings, you don't have a business and nothing plays," said Shapiro. "But having earnings is not the final answer either. They are a means to an end." The end is a strong economy, healthy communities and rising standards of living for Americans. By themselves, companies can't provide that, not without supportive economic and political policies, and that is a challenge that society and government have not faced up to.