A study released yesterday charges that a substantial amount of the money the International Monetary Fund funnels to developing countries now goes to repaying old, high-interest loans made by private multinational banks, rather than to development projects.

This procedure amounts to an indirect subsidy for commercial banks, which are now owed about $75 billion by countries facing high food and fuel costs, inflation and other economic difficulties, according to the study by Howard M. Wachtel, a fellow of the Transnational Institute.

The Carter administration has asked Congress to appropriate about $4 billion for the IMF and other public institutions such as the World Bank, according to sources. Wachtel said much of that money will be sued to refinance commercial bank loans that were "not particularly credit worthy in the first place."

The Transnational Institute is associated with the Institute for Polcy Studiies, a private Washington research organization.

A second new Transnational study, sharply critical of the commodity policies of the United States and other rich countries, was co-authored by the late Orlando Leterlier, and Michael Moffitt. Letelier, the former Chilean ambassador to Washington, and Moffitt's wife were killed here last Sept. 21 when a bomb exploded in the car they were riding in.

Credit and trade issues have emerged as key areas of negotiation between the United States and developing countries since the sharp increase in oil and food prices after 1973.

The total debt of the developing world reached $180 billion in 1976, according to the Morgan Guaranty Bank. That was four times what it was in 1967. By 1978, the countries will owe $13 billion a year in interest.

Wachtel and Moffitt warned at a press conference that this rising debt may induce debtor governments to halt wage increases, curtail economic development, ban strikes by labor unions, curb imports and reduce the standard of living. They said that these measure come about as the result of demands by international lending institutions for "belt tightening" as a condition for granting more credits.

"Austerity as an economic policy tends to develop a symbiotic relationship with conservative regimes," said Wachtel. "Austerity measures can lead to political repression."

Wachtel's study cited a case in which a consortium of private commercial banks required Peru to devalue its currency, sell the state-owned fishing fleet and end government subsides to labor unions before continuing the loans.

Wachtel and Moffitt said that the loans of IMF and the World Bank help commercial banks avoid defaults by their debtors, instead of helping the countries develop their economies. U.S.-based multinational banks are owed an estimated $45 billion of the $75 billion indebtedness to commercial banks.

Wachtel said the banks are "so overbank the system like a house of bank or a world recession could crumexposed that the collapse of one cards." Thirty-five per cent of Egypt's export earnings go to paying foreign debts, and Somalia's foreign debt is now largeer than its gross national product.

The study by Letelier and Moffitt said that many countries' income from exports has not kept pace with global inflation. Many of them want the Carter administration to join a $6 billion fund to stabilize commodity prices and assure a fair return for their raw materials and food exports.

The administration has indicated it will support international commodity price agreements only if they reduce world inflation.

Moffitt charged that, in this, the administration has backed away from earlier promises by President Carter to give trade concessions. "The policy is not significantly different from that of the previous administration," he said.