Speaking at a function—one of many scheduled for him in his busy, four-day itinerary covering the cities of Mumbai, Hyderabad and Bangalore—Mr. Gates said the money was the "largest single initiative focused on a single country" by the Melinda and Bill Gates Foundation.

But many are skeptical, among them India’s Health Minister Shatrughan Sinha who, speaking at a public function, denounced U.S. Ambassador Robert Blackwill’s attempts to promote U.S.-led anti HIV/AIDS initiatives based on kite-flying projections that India would have 25 million AIDS sufferers by 2010.

Asked about the government’s questioning of the AIDS statistics cited by his foundation, Mr. Gates, during a visit to a voluntary agency where he met people with HIV, said what was important was the disease and not the figures.

Controversy has been building since Mr. Blackwill quoted the figures from a report released recently by the U.S. Central Intelligence. He also referred to $63 million spent by the United States for containment of HIV/AIDS in India over the last five years.

According to the CIA report, the spread of HIV/AIDS in India, Russia and China posed serious threats to international health and economy unless urgent measures, including vaccination, were taken to contain the disease in those countries.

In the report, the three countries—together with Nigeria and Ethiopia—are projected to outstrip sub-Saharan Africa in the number of people living with HIV/AIDS by 2010. The report says that an estimated 50 to 75 million people could be living with the disease.

Volunteer agencies that work on human rights issues linked to HIV/AIDS wrote to Mr. Sinha demanding that the government take a stand on the issue.

In a pointed reference to projections made separately by Mr. Gates and Mr. Blackwill, Mr. Sinha said: "I fail to understand how people holding such important positions can stand on our soil and say that India will have 25 million sufferers of AIDS by 2010."

He accused the Americans of spreading fear in India about HIV/AIDS and said he suspected that "false propaganda" was being used to help the interests of trans-national corporations and people who were against India’s "safety and security."

Possibly as a reaction to the controversy generated by the issue, Indian Prime Minister Atal Bihari Vajpayee did not show up at a high power lunch with Mr. Gates, who instead went to meet him briefly at his residence.

Mr. Sinha too declined to meet Mr. Gates and flew off to the bustling port city of Mumbai.

Earlier this year, the health ministry said there were 3.97 million people infected with the virus that could lead to AIDS. The figures, derived from a report by the ministry’s Sentinel Surveillance Survey, said the spread of the virus had been contained.

In the past, the ministry has expressed extreme annoyance at figures released by UN agencies that differed from its own.

For example, the ministry objected to figures released by UN agencies in 2000 that said 310,000 Indians had died of AIDS in India the previous year but did not care to explain how that figure was arrived at. The figures were later retracted.

Different international agencies have continued to cite other statistics on how many Indians were dead or dying from HIV/AIDS.

"Every year we update our information and we are surprised to see other figures cited freely,’’ Mr. Sinha said.

Mr. Gates said the $100 million grant would be used for programs that focus on mobile populations such as truck drivers and migrant laborers who are considered to be at higher risk of acquiring and spreading HIV/AIDS.

Last year the Gates foundation issued a $100 million challenge grant to U.K.-based International AIDS Vaccine Initiative, which has since signed an agreement with the Indian government to develop a vaccine to specifically target prevalent strains in this country.

Ethnic Indians form 20 percent of Microsoft’s engineering force and Mr. Gates said this led him to have a special interest in India, a country he is visiting for the fifth time and where the company maintains software development centers.