The world's richest man, Bill Gates, says he is donating $100 million to fight AIDS in India. Indian officials said they welcome Mr. Gates generosity, but they dispute figures he is citing in saying India is facing an explosive AIDS epidemic.

Bill Gates, the chairman of giant computer software company Microsoft, said the foundation he and his wife established several years ago will spend $100 million over the next five years to fight HIV and AIDS in India.

Experts say there are at least four million AIDS cases in India the second-highest number of such cases after South Africa. Mr. Gates said his foundation's work will focus on vulnerable populations in India, such as truck drivers and migrant laborers.

"A lot of the focus will be on the mobile populations. Mobile populations are very much at risk for AIDS and, also, they are very much a factor in spreading AIDS into the general population. So we are working with partners to find creative ideas to educate and change behavior in those mobile populations. We are also very interested in educating people so that the stigma around the disease is reduced," Mr. Gates said.

Bill Gates and Microsoft have played an important role in helping to develop Indias information technology industry. The only Microsoft software development center outside the United States is in India.

Indias business leaders said they welcome Mr. Gates gift, saying their country faces a potential AIDS epidemic that could hurt Indias economy.

Mr. Gates's visit has generated controversy, because of figures he cites from a recent report released by the U.S. National Intelligence Council. The council predicts the number of AIDS cases in India will rise from the current four million to more than 20 million, by the end of the decade.

Indias health minister has accused Mr. Gates of spreading panic, claiming the report is completely inaccurate. Indian government officials said AIDS-prevention programs are having their intended effect and that the number of AIDS cases has stabilized, over the past three years.