The United States and four major European allies are considering trying to make Zaire President Mobutu Sese Seko accept outside control of Zaire's key institutions in exchange for providing his floundering government with military and financial help.

But such is Mobutu's reputation for autocratic touchiness that diplomats have expressed private skepticism about his readiness to accept, much less carry out, reforms one specialist desribed as tantamount to "making him a ward of court."

Top American, Belgian, British, French and West German civil servants planning to meet here today to discuss Western policy toward Africa, however, were reported to want to drive a hard bargain with Mobutu.

Whatever Western illusions remained about Mobutu's willingness to implement long overdue reforms in Zaire disappeared when he did nothing to improve a worsening situation after France and Morocco in 1977 helped crush an earlier threat in Shaba Province.

The most immediate problem facing the Paris conference remains fleshing out the Western-financed and partially equipped African expeditionary corps being formed to take over from Belgian and French troops now expected to leave Zaire in the coming week or so.

The West, especially France, would like to avoid having troops provided entirely by former French colonies such as Morocco, Senegal, Gabon and Togo.

Stripped of its rhetoric, the Western plan closely resembles the original United Nations operation in the former Belgian Congo from 1960 to 1964 when thousands of foreign troops kept a modicum of order and U.N. officials staffed key government jobs.

Even before the current Shaba fighting erupted, the International Monetary Fund had scheduled a meeting June 13 and 14 in Brussels to discuss tough conditions for saving Zaire's worsening economy.

Symptomatic of the IMF concern about Mobutu's lax attitude toward state finances were reported suggestions that an IMF official occupy the number two slot in the Zaire National Bank with veto power on foreign exchange allocations.

Under reported consideration were measures to strip Mobutu of much of his real political power and appoint veteran administrators with extensive prerogatives in the provinces.

Meeting today without a fixed agenda, the Western conferees are expected to make recommendations to their governments about wider African problems such as the now two-year-old French plan for a $2 billion African development plan.

Practical results from the meeting, however, may be extremely slim, according to diplomats close to the preparations.

They also noted Belgian and especially French irritation with the United States for announcing what they had hoped would remain a private meeting.

Their irritation in part stems from serious domestic political problems provoked by the Zaire events in Belgium and France in contrast to the stirrings of strengthened executive power discernible in the Carter administration's handling of the crisis.

In Belgium, Premier Leo Tindemans' coalition government reflects the basic split in the country at large. Dutch-speaking Flemings are generally more hostile toward doing anything at all for Zaire and more suspicious that the French will be tempted to take over the enormous Belgian economic interests in Zaire than are the French-speaking Walloons. Most Belgians working in Zaire are French speakers.

In France the Gaullists took exception to the American announcement of the Paris meeting during the annual summit of the North Atlantic Treaty Organization.

Gaullists, who initially backed the French paratroopers' intervention in Kolwezi, now have joined the opposition left-wing Socialists and Communists in attacking President Valery Giscard d-Estaing's African policy.

Central to Gaullist thinking is opposition to any effort, especially American-led, like this week's attempt by the Carter administration to extend NATO responsibilities beyond Europe and the Mediterranean.