NEW YORK (AP) _ The United States lost its financial bearings in the late 1970s and 1980s, not slowly but in a rush, as if institutions that once locked pennies away suddenly sought to force millions on borrowers.

Billions of dollars were sent abroad to earn the high interest rates that less developed nations were willing to pay, while some of the same banks were turning down American homebuyers seeking mortgages.

The money people claimed to know what they were doing too, that as bankers they could tell a good customer from a bad one. They were warned that loans to less developed countries could turn bad. Nonsense, said many well-known bankers.

Individuals saw the phenomenon in the form of letters urging them to accept bank cards with ''built-in'' lines of credit, a surprising turn, they mused, since the same bank wouldn't have given them a dime a year or so before.

And, as we are reminded again and again in these days of big debt, budget deficits, rising taxes, bankuptcies, high interest rates and recession-like economic activity, the people of the 1990s will pay for it.

In a discussion on corporate takeovers earlier this year, William M. Kearns Jr., managing director of Shearson Lehman Brothers, graphically compared the old days with the new in a way that few in his audience could forget.

Back in the late '60s and early '70s, he said, ''if Wall Street was going to do a hundred-million (dollar) bond offering for somebody like Exxon, they would inspect all that company's properties.'' That was just the beginning.

Then, ''representatives from all the major underwriting firms - First Boston, Salomon Brothers, Goldman (Sachs) - would sit down and talk with Exxon's CEO, CFO (chief executive and chief financial officer) and other officers.

''You'd go through a 'CIA' due-diligence study of a triple-A credit in order to float a hundred-million-dollar offering.'' All this for a relatively small loan to one of the most financially secure companies in the world.

''Then we hit '86 or '87. A guy you've never seen walks into your building and says, 'I've got a million bucks. Can you lend me one-hundred-million dollars?' And Wall Street would say, 'Sure. . . Step right over here.' ''

Simon Business, the magazine of the University of Rochester's graduate school of business administration - named for William E. Simon, former Treasury secretary - recently published some of Kearn's remarks revealing the extent to which standards were lowered.

Referring to the easy money, Prof. Gregg Jarrell asked him: ''So the door was opened to corporate raiders?''

Kearns responded: ''Yes - to black-hat guys who never should have been financed by Wall Street.

''In those days, you didn't need a lot of money to buy a major asset. Accessibility to money increased, either through banks or through junk bonds. People were putting up 2 percent and borrowing 98 per cent.''

In a typical deal, said Kearns, you could put up 10 percent in equity, obtain secure debt financing on 50 percent to 60 percent, and then, for the balance, offer unsecured, subordinated (call it third-rate) debt to investors.

That's the mentality and morality that led to savings and loan disasters, the downfall of securities firms, a bear market, and the shaky structure of many banks. It probably has led also to the recession of 1990. End Adv AMs Wednesday, Oct. 3