Nobody needs to tell Robert Lackovic how powerful federal banking examiners have become.

For the better part of three months the chairman of First Nationwide Bank, based in San Francisco, watched as 30 examiners from two government agencies pored over the thrift's financial records.

When they finished, the examiners demanded that $250 million in additional cash be pumped into First Nationwide by its owner, Ford Motor Co.

Ford is no pushover when it comes to dealing with bureaucrats, having recently beaten back government demands to improve the fuel efficiency of its cars. But when the examiners insisted on more capital for First Nationwide, Ford promised the money without a protest.

"They are much tougher," Lackovic said. "They are examining people in much more detail. They pored through the portfolio a lot more than they used to. Maybe if we had been examining institutions like this four years ago, we wouldn't have the problems we've got."

Crises in the nation's savings and loan and banking industries are costing taxpayers tens of billions of dollars and are straining deposit insurance funds. In response, federal bank examiners have cast off their green eye shades and I-get-no-respect demeanor to take up the most influential role they have ever played in shaping the economy.

Once regarded as little more than traffic cops for bookkeepers, bank examiners today make critical decisions that affect every American.

Bank examiners -- many are relative newcomers in their twenties or early thirties -- are deciding which banks will survive and who will run them, what businesses will get loans and what kind of loans they will receive. Ultimately these examiners could be a major factor in determining whether the nation will suffer a recession and how bad any recession would be.

These new roles have made the issue of bank examinations and their effect on bank lending practices so important that President Bush and members of his Cabinet have talked about the topic four times in the last 10 days as part of a broad review of the economic slowdown.

After hearing complaints from business executives that overzealous bank examiners are making it difficult for businesses to get needed loans and may even be adding to the likelihood of a recession, Bush acknowledged that banks now are paying the price of their "excesses" during the 1980s.

"We had kind of go-go lending policies in some of our financial institutions," Bush said. "Loans were made then that wouldn't be made now."

This newly recognized mission of protecting the nation from imprudent bankers has made major Washington players of government officials who once settled for bit parts in economic policy making:

Federal Deposit Insurance Corp. Chairman L. William Seidman has become so controversial and powerful that White House Chief of Staff John Sununu tried to get rid of him -- and failed.

Comptroller of the Currency Robert L. Clarke is the first person holding that office ever to attract television coverage to his press conferences.

Office of Thrift Supervision Director T. Timothy Ryan has taken a job that President Reagan once gave to one of his public relations men and turned it into a high-visibility post that could earn him a shot at a Cabinet office.

At the Federal Reserve Board, where Chairman Alan Greenspan has long been a powerful figure, the director of the Division of Banking Supervision and Regulation, William Taylor, has emerged from the obscurity of the Fed's bureaucracy to earn President Bush's endorsement to succeed Seidman at the FDIC.

The four agencies share power over often-indistinguishable financial institutions. The Office of the Comptroller of Currency regulates 4,000 national banks. The Federal Reserve oversees 1,073 state-chartered banks that chose to belong to the Fed and all bank holding companies.

The Office of Thrift Supervision regulates 2,404 savings and loans including many that call themselves savings banks. The FDIC has responsibility for state banks that are not Federal Reserve members and examines all thrifts as well.

Together, the agencies marshal about 38,000 employees to watch over the health and safety of more than $3.9 trillion of the nation's wealth.

At a basic level, the bank examiner's job is simple: Examiners periodically visit banks to review records to ensure that federal regulations are being followed and that the banks' public financial reports reflect what is happening at their loan desks and in their boardrooms.

In the current climate, the clout of the four regulatory agencies has grown to such proportions that a dark joke made the rounds this past week at the convention of the U.S. League of Savings Institutions, the trade group for the S&L industry. Question: "What's the difference between a bank regulator and a terrorist?" Answer: "You can negotiate with a terrorist."

It is the take-no-prisoners attitude shown by examiners that has provoked the recent discussions at the White House and Camp David.

Ford's First Nationwide, a chain of thrifts operating in nine states, is one of hundreds of financial institutions that as a result of an examination were forced to write off more bad loans, set aside cash to cover expected losses and strengthen financial bases by raising new money from owners. First Nationwide added $115 million to its loan-loss reserves and is still negotiating with the FDIC over issues that Lackovic said could lead to further write-downs.

Lackovic said his company disagreed with the examiners over "only a handful" of loans, but the aggressive stance taken by regulators is leading bankers to change the way they do business. "It's going to force people to get a little more conservative than they might normally be because you're afraid of being criticized," he said.

When bankers are warned about certain kinds of loans, Lackovic said, "They just hunker back and say 'Well, if you don't like this kind of loan, we won't make them anymore' and start to curtail their activity."

The central question in the White House debate about examination practices is whether the regulators are the cause of a lending slowdown or merely agents of reality, motivating bankers to do what they already know they should be doing.

Clarke, as currency comptroller and a top banking regulator, said in a interview with Reuter: "We have to maintain proper lending standards and proper supervisory standards to keep the banks in business." He dismissed criticism that his tough policies are pushing the nation into a recession.

Commerce Secretary Robert Mosbacher and White House Chief of Staff Sununu lead the administration faction maintaining that regulators have gone too far.

On the other side of the issue are Treasury Secretary Nicholas F. Brady, Fed Chairman Greenspan and Michael J. Boskin, chairman of the President's Council of Economic Advisors, who said regulators have became scapegoats for the economy's problems.

And a few experts outside the government, led by California economist Dan Brumbaugh, said the regulators are not being tough enough.

Bankers can be found on both sides of the issue.

In New England, about 20 percent of the real estate problems stem from "overzealousness by regulators" and about 80 percent of the problems are because of "overzealousness by bankers" said Guilliaem Aertsen, who is in charge of New England real estate lending for the Bank of Boston.

"We in the bank rely heavily on suggestions from our regulator friends. We take most of them," he said. "The fact is the real estate markets are down. Banks need to review their ... practices."

As Bush pointed out last week, real estate lending practices grew too loose during the past decade and the questionable loans now are haunting the banks that made the loans.

Lending standards were relaxed, one federal regulator stationed in New England said, "because people wanted ... to take business away from someone else."

Banking regulators bear some of the responsibility for allowing the rules to be relaxed, bankers and regulators conceded, because the liberalization of lending standards went on with their full knowledge and approval.

"The better time -- and the harder time -- to do something about it was at the beginning," one congressional banking expert said.

But as the New England regulator said: "It is hard for any regulatory authority to discipline a bank when it has no obvious weaknesses."

A complaint often heard at the savings and loan convention last week was that regulators were overcompensating for their past mistakes, particularly their failure to move quickly when Southwest banks and thrifts got in trouble five years ago.

"They're covering their backsides so much, they're going to get diaper rash," said Donald R. Shackelford, the new chairman of the U.S. League of Savings Institutions.

There is no question that banking regulators have extraordinary power over the institutions they oversee, including regulatory tools that no other federal agency is permitted to exercise. A frequent lament of beleaguered executives is that "bank regulators are God."

For example, Congress has given the FDIC authority to issue orders stopping "any specific activity which poses a serious threat" to the deposit insurance fund. The Office of Thrift Supervision can act as both prosecutor and judge and has accused several thrift executives of looting their institution and ordered them to give back the money.

Historically the bank examiners' power has been wielded with discretion, even reluctance, but as the problems of the banking and thrift industries have worsened, the banking agencies have used all the tools at their disposal.

When the Office of the Comptroller of the Currency took over the National Bank of Washington earlier this year, it used for the first time its power to seize a faltering financial institution before it actually became insolvent. The power came from the S&L cleanup law passed in 1989, when Congress granted the regulators' request for additional authority.

In the past few months, regulators have demanded the firing of the president of Perpetual Savings Bank, the largest thrift in the Washington area, and ordered another local banking company, James Madison Ltd., to close branches and reduce operations.

Even tighter controls have been imposed on MNC Financial Corp., the company that owns Maryland National Bank and American Security Bank. The holding company has been given a March 31 deadline for raising new capital and has been ordered to sell its prized credit-card business and to stop paying dividends to stockholders.

Such orders often are issued in secret. While they theoretically can be appealed to a court, banks are reluctant to publicly admit they are being disciplined and thus rarely put up a fight.

When bankers do fight, they lose. The FDIC has survived every court challenge to its supervisory powers.

Thrift regulators last summer won a landmark court decision when U.S. District Court Judge Stanley Sporkin threw out a challenge to its authority brought by Charles H. Keating of the failed Lincoln Savings and Loan Association of Irvine, Calif.

And even after a Kansas thrift won a district court decision against the Office of Thrift Supervision a few months ago, the agency used other powers to keep management from regaining control of the institution.

Staff writers John M. Berry, Joe l Glenn Brenner and Robert J. McCartney contributed to this report.