Drug company GlaxoSmithKline plans to invest up to $US97 million over 10 years to improve research, development and access to AIDS drugs in Africa.
It has issued a free voluntary licencing agreement to a South African manufacturer to produce a cheaper generic version of its AIDS drug abacavir, or Ziagen.
Glaxo took a lead in February by promising to place many of its patents on drugs for tropical diseases into a free "pool", but it stopped short of offering patents on medicines for HIV/AIDS.
So far Glaxo is the only big drug company to have committed to pool some of drug patents, although it was joined in the initiative last week by US biotech company Alnylam Pharmaceuticals.
Its new investments will see up to Â£50 million channelled into a fund to support non-governmental organisations working with pregnant women to prevent mother-to-child transmission of HIV.
A further Â£10 million in seed funding will go to support public-private partnership work in developing AIDS medicines specifically for children.