The investment, she said, showed Britain was leading the way in international aid and claimed the contribution would save a life every three minutes, Daily Express reported Tuesday.
The aid will fund lifesaving anti-retroviral therapy for 750,000 people living with HIV, 32 million more insecticide-treated nets to prevent the transmission of malaria and TB treatment for over a million people.
The Global Fund was created in 2002 as a public private partnership to raise funds to significantly change the course of HIV/AIDS, TB, and Malaria. Britain is the third largest donor, after the US and France.
Speaking at the UN General Assembly meeting, Greening said: "AIDS, TB and Malaria are among the world's biggest killers despite being entirely preventable and treatable.
"The Global Fund has already helped save millions of lives but we must keep up the momentum if we are to beat these diseases for good.
"It is in all our interests to help people live longer, healthier, more productive lives so we all need to play our part in working towards a world free of HIV/Aids, Malaria and TB."