Make credit available for the hard-pressed developing countries: That's the advice of three former top government financial advisers, when asked how to deal with the global debt crisis.
As if to reinforce their point, 35 international banks formed here Jan. 11 the Institute of International Finance (IIF) as an unofficial clearinghouse on foreign debts. The feeling here is that the present worldwide recession, longest since World War II, is manageable but that it still might take a turn for the worse.
The three financial advisers pressing President Reagan and Congress to help underwrite more loans to debt-burdened countries are Henry H. Fowler, former secretary of the Treasury and now chairman of Goldman Sachs International Corporation; W. Michael Blumenthal, former secretary of the Treasury, now top executive of the Burroughs Corporation, and Charles Schultze, ex-chairman of the Council of Economic Advisers and currently at Stanford University.
Other witnesses appearing before a continuing Senate subcommittee under Charles McC. Mathias (R) of Maryland make the same argument: The world economic crisis is manageable but needs international action; if not properly handled it could yet precipitate a 1929-type depression.
''It's the most serious situation since the thirties,'' testified Mr. Fowler. ''I don't recall any period equally somber,'' said Mr. Blumenthal. ''Developing countries of the world,'' said Mr. Schultze, ''are facing a series of developments - including obtaining new credit - which are sharply worsening their situation and contributing to the general worldwide recession.''
A critical moment may lie just ahead, witnesses said, when the Reagan administration asks Congress to increase US contributions to the International Monetary Fund and similar international groups, so they in turn can make more loans to developing countries.
Nations like Argentina, Brazil, and Mexico have received billions of dollars worth of loans from hundreds of US banks and they are threatened with default. Other countries watch US precedent. Mr. Fowler said: ''The treasuries and central banks of the developed industrial nations have become engaged in a giant and complicated operation to work with the authorities of the borrowing nations, and the private international banks, to work out the debt problem.''
Why should the US help have-not nations, and their sponsors on Wall Street, demanded Sen. William Proxmire (D) of Wisconsin, a member of the Mathias panel, while refusing funds to ailing industries at home? ''A lot of people feel this bailout may lie beyond the control of the IMF. And if we are going to extend $9 billion in credits to the IMF why shouldn't we give it to the auto and housing industries here?''
Thus, the prospect opened of possible split between the White House and Congress: The President wants the US to help underwrite more IMF loans while Congress is thinking of the US deficit.