Federal Reserve Board Chairman Paul A. Volcker and heads of the two other major government bank regulatory agencies yesterday continued to resist congressional pressure to limit the amount of money American banks can lend to borrowers in each foreign country.

Instead, they gave the Senate Banking Committee details of a five-point, nonlegislative program to improve the supervision and regulation of international lending that they said would induce banks to be more careful than they had been in the past.

The five-point Joint Memorandum was submitted by Volcker, Federal Deposit Insurance Corp. Chairman William Isaac and Comptroller of the Currency C. T. Conover to Banking Committee Chairman Jake Garn (R-Utah). Among other things, it would require banks to set up special reserves against certain categories of shaky debts, recognizing the lessened quality of those loan assets.

When Sen. William Proxmire (D-Wis.) told Volcker that the Joint Memorandum was a "soft approach," Volcker responded:

"It's not meant to be soft, senator. It's meant to leave room to adjust to circumstances." In his prepared testimony, he complained that the country lending limits set out in a bill introduced by Proxmire and Sen. John Heinz (R-Pa.) would be "too rigid" and would fail to distinguish between countries that can carry substantial debt and those that can't.

But prodding by Proxmire elicited the fact that Isaac, at least, might have been willing to come forward with a somewhat tougher Joint Memorandum, and that all are willing now to see their reform recommendations translated into a legislative proposal. Isaac and Conover said they supported that idea, and Volcker said he was "not opposed."

Isaac said that the major disagreement among him, Volcker and Conover was in defining the point in time when a threatening situation requires a bank to set up special reserves against potential loss. "I believe we should be reserving at an earlier point," Isaac said.

Their compromise proposal on this point refers to a situation when a borrower "has been unable to service its debts over a protracted period of time." It would set up a new regulatory procedure for countries categorized as "reservable," a status that would come into effect in any of the following circumstances:

* Full interest payments had not been made for more than six months.

* The terms of restructured debt had not been met for more than one year.

* International Monetary Fund adjustment programs had not been complied with, "and there is no immediate prospect for such compliance."

* No definite prospect exists for the "orderly restoration" of debt service in the near future.

Against the warnings of Heinz and Proxmire that the Senate might reject the administration's request for $8.4 billion in new appropriations for the IMF unless it is coupled with legislation "that will prevent a recurrence of the current debt crisis for U.S. banks," Garn warned against overkill.

"We shouldn't ask for retribution from the banks, like country loan limits," Garn said. "We're flirting far beyond what is necessary to deal with this situation." He caustically criticized corrective legislation that has originated in the House as "satisfying a political need."

Volcker said that the more or less voluntary corrective proposals that he, Isaac and Conover had submitted to the Senate and House banking committees last week are designed to maintain international lending by American banks, while encouraging them to "maintain adequate financial strength to deal with unexpected contingencies."

The Joint Memorandum says that "those institutions with relatively large concentrations of credit will be expected to maintain generally higher overall capital ratios than those institutions that are well diversified. As part of this process, the banking regulators will further develop, as a reference point, standards for country exposure concentration as it relates to capital adequacy."

Proxmire and Heinz argued that the Joint Memorandum's use of the phrase "will be expected" was not strong enough to assure the desired result.

Volcker's response was that "examiners will be more aggressive" in applying the present program of country risk evaluation that was first established in 1979.

But Isaac responded to a question by saying he doubted that more aggressive examination by itself would reduce future risks, and said he was placing his reliance on more complete "disclosure and market discipline."

Conover said he was counting not on any one of the recommendations, but a combination of the proposed reforms, that include for the provision of special reserves against certain country exposures.

The other reforms in the Joint Memorandum would establish uniform rules on fees, including rescheduling fees, "so that artificial incentives are not created for foreign lending," and for better cooperation with foreign regulatory bodies and with the IMF.