Under the best of circumstances, the International Monetary Fund will need another emergency loan of between $6 billion and $7 billion from major nations in 1984 to cope with the global debt crisis, according to West German Central Bank President Karl Otto Poehl.

Poehl conceded in an interview that it will be difficult to raise that much money in view of the already evident reluctance of the U.S. and European governments to strain their budgets to create additional resources for the IMF.

Poehl made the assumption that two critical events helping to replenish IMF funds will already have taken place by the end of the year: approval by Congress of the $8.4 billion IMF bill, which will pave the way for other countries to pay in their larger quotas; and a $6 billion "bridging loan" split equally between European central banks and Saudi Arabia.

That $6 billion would cover what IMF Managing Director Jacques de Larosiere has called the "commitment gap" by the end of this year--that is, the excess of the IMF's firm commitments in excess of money in hand. At that stage, the IMF expects to begin collecting money from the 48 percent enlargement of quotas, which will provide about $15 billion in hard currencies, usable for loans.

But Poehl said that won't be enough, inasmuch as the Interim Committee, in its marathon session over the weekend, agreed to keep its "enlarged access" policy in effect for one more year, allowing nations--on the average--a borrowing ceiling equal to 1983.

De Larosiere himself hinted at this situation in his annual address on Tuesday, although, unlike Poehl, he didn't put a price tag on the new needs.

"The financing of such an enlarged access policy will require further borrowing by the fund over the next few years," de Larosiere said. "This is all the more important because adjustment and debt problems will be with us for a number of years to come."

Despite reports this week that prospects had improved for the European share of the $6 billion bridging loan--unlocking the Saudi half--Poehl said that "we Germans have not decided whether to participate." He observed that West Germany already had some 20 percent of its reserve assets tied up in the IMF.

He cited three conditions that had been set by the Germans. The first is a limitation on IMF lending, as sought by the American government. Poehl termed the compromise achieved last weekend "very crucial" and "a good solution--I'm very satisfied with that."

Second, there is the critical question of the U.S. appropriation for the IMF--$8.4 billion, including $5.8 billion for larger quotas and $2.6 billion for the General Agreements to Borrow, a separate "crisis" fund that the IMF can tap. "I can't imagine that the United States Congress would not accept this responsibility," Poehl said.

And third (although of a lower order of importance), Poehl raised the touchy issue of the U.S. refusal to participate in the current $6 billion bridging loan. Even though they understand that the administration does not want to lay yet one more demand on Congress, it irks Europeans, he said, that the United States has been excluded from this extra demand by the IMF. "Why shouldn't the United States participate?" Poehl asked rhetorically.

He strongly intimated that once Congress passes the IMF legislation, and the Europeans and Saudis advance the $6 billion, they would look for "some gesture" from the United States.

After listening to both Treasury Secretary Donald T. Regan and Federal Reserve Chairman Paul A. Volcker during the Interim Committee meeting last weekend, many Europeans said privately they expected innovative forms of additional U.S. contributions, perhaps as purchases of special drawing rights (SDRs) or as export credits for major Third World countries.

At a press conference yesterday, Regan crisply answered "No!" when asked if there was any chance that the United States would participate in the $3 billion European loan, once the $8.4 IMF appropriation is passed. "Why not?" a reporter pressed.

"No money," Regan responded. But in answering another question, he noted that the United States has pledged $1.25 billion in Export-Import Bank credits as part of the latest Brazilian package.

As for the $6 billion to $7 billion package that Poehl sees as needed next year, he said that one solution to the problem would be to activate the enlarged GAB pool, assuming that the $8.4 billion total appropriation goes through.

"But Don Regan talks tough on that," Poehl conceded. The U.S. position is that the GAB money should not be used to supplement normal IMF resources, but only in case of an expected global crisis. Another route would be for the IMF to borrow in the commercial market.

"But we all are very concerned about the IMF going to the market," Poehl said. "It opens a Pandora's box. The commercial banks would like very much to lend to the IMF, and not to the developing countries. That would be too close to a bailout."

Prior to his address to the joint session, Regan said yesterday the administration would "do more if possible" than the $750 million annually he had set as a limit for American contributions to the International Development Association, the World Bank's soft-loan arm. But he cautioned that "the mood of our Congress is not predisposed to give extra-large sums of money to the World Bank."