The International Finance Corp. yesterday offered a gloomy perspective on the outlook for private business in most of the Third World, despite a general improvement in international economic prospects.

Nonetheless, the IFC -- an affiliate of the World Bank -- said in its annual report that after several years of slow growth, it had significantly boosted the number and volume of its investments for private business ventures in the developing countries last year.

"It is ironic that the private sector is coming more into favor just when private firms in so many of the [Third World] countries are weakened from the events of the last few years," the report said.

Both the World Bank management and major shareholders such as the United States have been giving new emphasis to the role of the private sector in the development process.

The IFC aims to more than double the size of its investments in the Third World over the next five years. But the report warns that the "minimum level of stability and prosperity" needed for private enterprise to expand and flourish is not yet present.

Sir William Ryrie, executive vice president of the IFC, said that the agency's increased activity "is ample evidence that even though many developing countries are facing difficult economic conditions, there are good investments there."

A total of 75 projects, 21 more than the prior year, were approved by the agency, involving $609.3 million of net investments, an increase of 56 percent. The IFC estimated the total capital costs of these investments at about $2.8 billion.

Ryrie, who is trying to raise the profile of the IFC in world banking circles, said that the agency is "back onto a high growth track," attracting private capital into Third World ventures that it might otherwise pass up.

Nonetheless, the text of the annual report contained some sober analysis of the Third World investment climate. It called attention to IFC's accurate forecast a year ago that, although most analysts had said that the Third World debt crisis had been managed successfully, significant problems would remain for private enterprise in these countries.

Among those cited were the weak cash flows and low profits of private companies, resulting in bankruptcies, takeovers by governments and many mergers and consolidations.

The report said that the private investment climate is best in the export-oriented countries of Asia, such as South Korea, Malaysia and Thailand, as well as others such as Colombia, India, Cameroon and Indonesia "that did not contract too much debt."

In countries such as Peru and Zambia, where debt is high and they must rely heavily on non-oil commodity exports, prospects for private enterprise are worst.

In most of the other more advanced developing countries, such as Brazil, Mexico, Turkey and the Philippines, "the depressing effects of recent stabilization and adjustment programs still dominate the private investment climate . . . ," the report said.

The IFC is attempting to secure a doubling of its capital to $1.3 billion to support the expanded five-year program. Necessary approval has not yet been voted by Congress, although 71 percent of member nation votes thus far have been cast in favor of the capital increase -- four percentage points short of the 75 percent required for approval.