The accelerating movement to force universities to divest from corporations doing business in South Africa has taken on an important new twist: Moral arguments aside, its advocates say divestment may make better business sense.

They cite the experience of schools that have divested in the last decade, and interviews with financial counselors here indicate they may be right.

Since the divestiture campaign took hold in the late 1970s, more than 30 universities have taken some kind of divestment action, usually freezing new investments or withdrawing from firms that have not endorsed the so-called Sullivan principles, prescribing equal employment opportunity for blacks in South Africa.

In addition, about a dozen schools have sold all their interests in firms dealing with South Africa. These include Howard University, Antioch College, Michigan State University and the University of Wisconsin.

Those schools that have completely divested report that withdrawing from South Africa-related corporations did not hurt their portfolios. Officials at some -- such as Michigan State -- report that their endowments may have increased in value as a result of divestiture.

"If you took the portfolio we divested and looked at what it would have been one year later, versus the market value of the portfolio we purchased, the market value was $1 million more," said Nancy Craig, director of investments and trusts at Michigan State in East Lansing. "It was not an economic hardship and still isn't."

According to officials of those schools that have divested, as well as investment counselors and several recent surveys, divestment has enabled schools to back away from the larger automobile and petroleum companies, which showed sluggish economic performance, and invest in smaller, domestic companies and high-technology firms, which showed the most growth in the first half of this decade.

"In almost every study," said Robert Schwartz, vice president of Shearson-American Express in New York City, "performance is better without the South Africa-related stocks and bonds."

Universities with and without South Africa-related investments also have turned increasingly to direct investments as a safe, profitable haven for their dollars. Many schools are investing their money directly in housing projects and commercial buildings.

But most of those schools that have divested manage relatively small endowments, and the shift was easily accomplished. Now the pressure is building for the better endowed schools to follow suit -- and their multimillion dollar portfolios may not be so easily changed.

For divestment advocates, the "second tier" of targeted universities includes Ivy League schools such as Harvard and Yale, which have sold some South Africa-related stock, and Columbia University here, which has about $34 million in South Africa-related holdings.

As campus unrest grows -- with some student protesters now relying on statistics over sloganeering -- university administrators and financial officials are rethinking the value of South Africa-related investments. But the activists appear to be becoming less significant than investment bankers and money managers who can talk the dollars and cents of divestment.

One of those is Schwartz, an investment counselor whose own view differs from that of his firm. Schwartz recently traveled the country telling universities how they can divest from corporations that deal with South Africa while increasing the value of their portfolios.

Schwartz cites studies by the Investor Responsibility Research Center, which found that over a 10-year period, portfolios free of South Africa-related investments performed better than those same portfolios would have had they not been divested. "The performance without South Africa in almost every major study has been better," he said. "My position is that if consistently your performance is better, then why look at tangible factors? Making money is the name of the game -- that's the bottom line -- so let's get down to business."

Another investment counselor who has testified that divestment can be profitable is Mary Murningham, president of the social-investment services division of Mitchell Investment Management of Cambridge, Mass. "Divestment," she said, "should not be a problem, just flat out. There are so many divestment alternatives available."

The most frequently mentioned example of successful divestment is Michigan State, which in 1978 and 1979 sold more than $7 million worth of stock in 13 companies that did business in South Africa -- including some blue-chip firms like Citicorp, IBM, General Motors, Ford, Exxon, Xerox and Dow Chemical.

To replace it, the university bought stock in smaller, mostly domestic firms like American Hospital Supply, Communications Satellite, and General Signal Corp. The result was a portfolio valued at $1 million more than the old one.

Still, divestment holds many problems, as even its advocates concede. Holding large shares of small- and medium-sized firms creates problems if the school later decides to liquidate its assets: The school could end up disrupting a company it largely owns. Also, as Craig at Michigan State suggested, it is often difficult to find financial managers able, or willing, to work under the constraints of a South Africa-free policy.

Larger questions enter the debate: Should politics and morality enter into a discussion of financial management and investment? What responsibility do multinational corporations have for perpetuating social change? And then there is the core question of the divestment debate: Can universities do more for black South Africans by using their stock holdings in American corporations as leverage?

Columbia's trustees, in its most recent reaffirmation of an earlier decision against divestment, said: "The more appropriate and effective policy is to influence the American corporations in which the university holds shares to conduct their business in South Africa in accordance with the broad moral and social ideals of American society."