The money will be doled out over five years to the Global Alliance for TB Drug Development to develop new drugs to combat a disease that kills nearly 2 million people a year. The four available drugs currently used to treat the disease are all more than 40 years old and take six months to work, while many patients have tuberculosis strains that are resistant to existing treatments.

"Tuberculosis is one of the world's oldest infectious agents and has always posed challenges for the scientific community," said Dr. Peter Small of the Seattle-based Gates Foundation. "New treatments could free patients from a grueling six-month regimen and, ultimately, save millions of lives."

The New York-based TB Alliance is developing 11 experimental tuberculosis treatments, with the drug moxifloxacin the most advanced candidate. The Gates grant would pay for a large human test of moxifloxacin, which TB Alliance hopes to begin distributing widely by 2010.

"This is a remarkable, remarkable shot in the arm for the alliance," said Maria Freire, TB Alliance's chief executive. "This grant offers the first real hope in a really long time." The alliance received a five-year, $25 million Gates grant in 2000.

The World Health Organization said one of its greatest concerns is TB's spread among HIV-infected people in Africa and a multidrug-resistant form of the disease, especially in former Soviet provinces in Eastern Europe.

Tuberculosis is the world's deadliest curable, infectious disease. Each year 8.9 million new TB cases are diagnosed and 1.7 million people die of the ailment, 90 percent of them in developing countries. China and India alone account for 35 percent of all estimated new TB cases each year.

The Gates Foundation has an endowment of $29.1 billion and has targeted TB as one of several diseases afflicting the Third World it wants to help eradicate. Earlier this year, Bill Gates said his foundation would boost its funding for TB eradication from $300 million to $900 million during the next decade.