Jacques de Larosiere de Champfeu, top civil servant in the French Treasury, and front-runner for the post of managing director of the International Monetary Fund, is a man who believes that the IMF must assume a greater role in world monetary affairs in years to come.

Larosiere, 48, received the informal blessing of the "Big Five" ministers of finance at a meeting in Paris on December 3. The IMF's Committee of the Whole is scheduled to meet on Thursday to take up the question of a successor to H. J. Witteveen, a Dutchman who announced some weeks ago he would not again be a candidate for a five-year term next September.

There are only two other announced candidates for the job apart from Larosiere, who has the support not only of the major industrial powers but also of Middle East nations. They are Willem Duisenberg, Minister of Finance of the Netherlands, and Lamberto Dini, an executive director of the IMF for Italy, Malta, Portugal and Spain.

But despite some rumbling of discontent because Larosiere does not hold ministerial rank, and therefore may be inhibited in dealing with Treasury secretaries and ministers of finance, his appointment is taken as 90 per cent sure at this point.

Larosiere has had wide experience in international financial affairs. He has been chairman of the deputies of the Group of Ten since September, 1976, and the French delegate to key policy committees of the Organization of Economic Cooperation and Development.

He was personal assistant and director of the Cabinet for Valery Giscard d'Estaing when the French President was minister of finance in 1974 - a close relationship that worries the Dutch backers of Duisenberg.

Larosiere made a highly favorable impression on American officials during the Jamaica negotiations of the Interim Committee in 1976 that led to agreement for a new IMF Article (IV) covering the surveillance of floating exchange rates.

Larosiere is known to feel that the role of the IMF will have to grow because the private banking system alone will not be able to handle the accumulation of official debt.

He is said to feel that a key function for the IMF will be that of surveillance, not simply in terms of exchange rates, but of the underlying economic conditions. He visualizes the IMF, along with the OECD, in an advising capacity, getting member countries to adjust their balance of payments deficits and surpluses.

This would inject the IMF into national economic polices not as an international overseer but at least as a consultant. He recognizes that this will be difficult and perhaps touchy area to define - but one in which the IMF should have more responsibility.

Sources in Paris and Washington say that Larosiere goes along with the conventional wisdom in international financial circles that the IMF's resources will have to be enlarged so that it can continue to play a major role in financing balance of payments deficits. He is likely to favor an increase of quotas in the 7th review of something more than 50 per cent, erring, if need be, on the high side.

On one of the big international economic issues of the next few years - the proper degree of "conditionality" for IMF loans - Larosiere is likely to insist that debtor countries adhere to stricter rules of conditionality than the IMF has demanded in recent years. But he would agree that the rules have to be adapted in each case, since some countries will need a longer adjustment schedule than others.

Larosiere is said to be sympathetic to the desire of the private banking system for some relationship with the IMF that would help protect the private banks' lending operations in poor countries. But like the current managers of the IMF, he is likely to be leery of any formal relationship with the private banking system.

On world economic problems, Larosiere goes along with the U.S. view that West Germany and Japan should pursue faster economic growth at home. He worries about protectionist tendencies, but is sympathetic to the French proposition that "orderly growth" of world trade is needed to prevent the collapse of specific industrial sectors in some countries. Friends say he approves the recently announced U.S. "reference price" system for steel as an intelligent way to handle a market that has become overwhelmed. But he cautions that this formula should be considered the exception to the rule.