When the Rev. Leon Sullivan speaks to business leaders these days, he invites them to join him in doing the "work of God" in far-off places. He is not talking about Bibles and converting the heathen of foreign lands. He is talking about the global economy.

Best known for his work against South Africa's old apartheid system, Sullivan has embarked on a bigger cause--to make multinational corporations more socially responsible. He is winning some brand-name converts in a business world that is normally allergic to moralistic rhetoric by activist preachers.

"What I'm doing is the work of God," said Sullivan, who rose to prominence in the 1950s as pastor of Philadelphia's Zion Baptist Church, a predominantly black congregation, and now lives in Scottsdale, Ariz.

That is a line he has delivered to audiences such as the U.S. Chamber of Commerce. "It's my ministry. It's practical evangelism. It's what the Lord wants me to do," he added.

In the late 1970s, he authored the so-called Sullivan Principles, a code of conduct for companies doing business in South Africa. It was the era of apartheid or racial subjugation there. No large, reputable business dared venture into the country without pledging to honor Sullivan's anti-discrimination code.

Now Sullivan is going global with a new corporate code. The prime target this time is inhumane working conditions, from New York to New Delhi. Although it is not fully clear how the voluntary plan will work, the new Global Sullivan Principles have already attracted a fair following of giant corporations.

"I'm using the carrot. I'm encouraging companies to do the right thing and act in concert with these principles," said Sullivan, whose main organizational base since 1964 has been the Opportunities Industrialization Centers of America, one of the oldest job training organizations in the country, with headquarters in Philadelphia.

Those broad principles include just wages and respect for the environment. While holding out the carrot, Sullivan alluded to possible pressure on companies by institutional investors including employee pension funds. "If necessary, I'll use the hammer," he said.

With 35,000 employees in a little over 100 countries, Chevron is one of more than three dozen transnational companies that have bought into the Global Sullivan Principles. Others include General Motors Corp., Pfizer, Proctor and Gamble, and Quaker Oats Co. As backers, they commit to paying workers everywhere enough to "meet at least their basic needs" and to equal opportunity in hiring and advancement, among other principles.

Like a proliferating number of other codes, most of them limited in scope, the far-reaching Global Sullivan Principles are aimed at filling a vacuum of labor and environmental standards in the global economy, particularly in the Third World.

But unlike activist groups that have badgered companies to clean up conditions in sweatshops, Sullivan is relying mainly on friendly persuasion and enlightened self-interest on the part of image-conscious corporations. For example, companies that are judged as abiding by the Sullivan code would gain a standard seal of approval and other forms of recognition as good corporate citizens.

Based on his track record in South Africa, where the old Sullivan Principles governed corporate conduct in the latter years of apartheid rule, many observers believe the 77-year-old minister has the moral standing to lead a global movement of corporate responsibility.

Certainly his followers in the business world think so.

"We have a lot of confidence in Reverend Sullivan. We believe in him. We believe he can make things happen," said Norm Zeiser, policy coordinator of Chevron Corp. in San Francisco. "He is very creative and has tremendous influence" on the thinking of industry leaders, he said.

At one time, corporations were hugely resistant to ethical codes embodying standards of social accountability imposed by outside organizations. Sullivan is widely credited with having converted companies on that point.

"It was clearly a paradigm shift that Leon engineered," said the Rev. Oliver F. Williams, a business ethics professor at the University of Notre Dame in South Bend, Ind. The shift was heralded by the original principles, which sought to end workplace discrimination in South Africa.

The idea was that citizens, communities, and consumers must "have a say in how you run your companies when it comes to ethical and social issues," said Williams, editor of a newly released collection of papers titled "Global Codes of Conduct: An Idea Whose Time Has Come." Published by the University of Notre Dame Press, the book includes an essay by Williams about Sullivan's achievements.

But even admirers like Williams, a Catholic priest who has worked closely with Sullivan in the past, are a bit skeptical. They are not sure how the new principles, filling less than two pages, will be put into practice and affect corporate behavior.