When the finance ministers and central bankers of the key nations -- rich and poor -- gather here this week in their roles as governors of the International Monetary Fund and World Bank, there will be plenty of hot topics on the agenda: the collapse of oil prices, lower international interest rates, and the dramatic fall of the dollar in foreign exchange markets since September.

The various meetings during a four-day period, beginning Tuesday, are more likely to provide an airing of views than any significant conclusions on any issues.

Nonetheless, advocates of a search for some formula to provide greater stability of exchange rates regard the next few days as a potentially important landmark in a developing process that has gained remarkable momentum in the past several months. And in any event, they will provide a backdrop for a Paris meeting of the Organization for Economic Cooperation and Development April 10-11, and the heads of government economic summit in Tokyo May 4-6.

The meetings this week, at the IMF headquarters here, will include:

*A session of the Group of Five -- the United States, West Germany, France, Japan and Britain -- to continue their discussions of the past six months on how to coordinate policy on exchange rates and interest rates. In their recent bilateral talks in Washington, President Reagan promised Prime Minister Brian Mulroney of Canada that he would support broadening the G-5 to a G-7 by including Canada and Italy.

*A session of the Group of 10 -- the seven nations mentioned above, plus Sweden, Switzerland, Belgium and the Netherlands (actually making 11 in all). G-10 Chairman H. Onno Ruding, the finance minister of the Netherlands, has urged that the G-10, rather than the G-5 (or G-7), be assigned the major role of coordinating international economic policy.

*A session of the Group of 24. This is the group representing the Third World nations within the IMF, who will be pressing -- as always -- for more aid to regenerate economic growth. The G-24 also will urge a reform of the international monetary system leading to less volatility in exchange rates.

*The semiannual meeting of the IMF's Interim Committee, which will discuss separate reports from the G-10 and G-24 on the question of international monetary reform, and ways in which the IMF will be expected to cooperate more successfully with the World Bank in easing the debt crisis.

*The parallel semiannual meeting of the joint IMF/Bank Development Committee, which is expected to focus primarily on the new role the bank is expected to play under incoming president, former U.S. congressman Barber Conable, who will replace A. W. Clausen at midyear.

Over the past six months, the most significant events bearing upon all of these related meetings have been the initiatives taken by the Unted States through the G-5 process to pull the dollar down and Treasury Secretary James A. Baker III's effort to create new hope in the Third World through what has become known as the "Baker debt initiative."

When Baker called a G-5 meeting at the Plaza Hotel last Sept. 22, which agreed on coordinated intervention to bring the dollar down, it marked a turnabout in the Reagan administration policy, which until then has followed a hands-off-the-market approach. Since then, the dollar has declined about 25 percent against the Japanese yen and other currencies, causing Japanese and European businessmen to pressure their politicians for at least a temporary effort to stabilize the present exchange rate relationships.

Later, Baker pressed at a London meeting of the G-5 for a coordinated reduction in central bank interest rates. The reduction came on March 6 and 7.

There has been great anticipation in international financial circles about what comes next, especially in view of President Reagan's charge to Baker in the State of the Union address to study whether greater stability of exchange rates is possible through the convening of a global conference.

But U.S. officials intend to bring no specific proposal to this week's session, or to the reprise that will take place in Paris on April 14-15 under the aegis of the OECD. "Our position is that we're going to next week's meetings to listen with an open mind. We want to see what the consensus is," a senior U.S. official said.

It is unlikely that a consensus will develop, however. French officials, as before, will argue for international monetary reform, calling for a "reference zone" system, sometimes called "target zones." Nations would establish under such a system acceptable ranges in which exchange rates could move, and would agree to adjust economic policies to keep rates within those zones.

But Secretary of State George P. Shultz, one of the designers of the floating rate system, has not accepted the idea of target zones. The West German government flatly opposes it. And Japan, which seeks more stability, is leery of the degree of rigidity in target zones.

For the moment, Treasury officials believe, the best solution is to keep building on the G-5 (or G-7) process, through which the major governments will continue to pressure each other for major adjustments in fiscal and monetary policy.

This time, in contrast to the sessions in New York and London, the Treasury will try to keep the G-5 (or G-7) in low profile, with as little media attention as possible. Said one senior official: "I think we will succeed. . . . It's easier to have anonymity when you're meeting in the same context with sort of larger -- well, easier to report news stories."

Those other stories will deal with:

The global economic outlook, and the impact of declining oil prices. The IMF last week revised its projections for global growth upward because of the drop in oil prices, the dollar and interest rates since its last analysis. But there are doubts about the Japanese economy; the uneasy situation of oil-exporter debtors, such as Mexico; and whether any effects on the U.S. economy, if the Gramm-Rudman-Hollings law takes hold, will be offset by adequate monetary ease.

The Third World debt situation. The focus here will be on the Baker debt initiative, and prospects for getting it off the ground through expanded lending by commercial banks and the multilateral development banks.

Separate World Bank issues. There will be a discussion, but no decision, on a general capital increase (GCI) for the bank. The U.S. position is that the bank has the capacity to lend an additional $2 billion a year for the next three years. If there is a "quality" demand for loans after that -- then and only then will a GCI get U.S. backing. But bank officials contend it is more clear now than it was at Seoul last year that the Baker initiative demands a GCI in the neighborhood of $35 billion to $50 billion.

IDA.There will be discussion, but no final action, on new "replenishment" of funds for the International Development Association for its IDA-8 program. At its last meeting in Paris, the IDA deputies agreed the IDA-8, three year program should be in the range of $10.5 billion to $12 billion.