Health ministers from Burundi, Ethiopia, Kenya, Mozambique, Zambia, Cambodia and Nepal will take part in the launch of the initiative at British Prime Minister Gordon Brown's office later on Wednesday.
Brown and German Chancellor Angela Merkel announced the creation of the International Health Partnership when they met in London last month.
Norway, France, Italy, The Netherlands and international organisations including the World Bank, the World Health Organisation, the European Commission and the African Development Bank have also thrown their support behind the programme, the British government said.
The Bill and Melinda Gates Foundation, the Microsoft chairperson's charity, is also involved.
Today we come together -- donor governments, health agencies and developing countries -- with the certainty that we have the knowledge and the power to save millions of lives through our efforts, Brown said in a statement.
The new partnership aims to reduce child and maternal mortality and tackle diseases such as HIV/AIDS by building long-term health infrastructure in developing countries and by improving coordination among donors.
More predictable funding
Donors will agree to work towards providing longer term and more predictable funding to poor countries to support their health plans.
Half a million women die each year in childbirth, while 10-million children do not reach their fifth birthday and only one in four of those in need of HIV/AIDS treatment in Africa receives it.
Britain's Department for International Development said that, while programmes to combat specific diseases in developing countries had brought good results, less attention had been paid to strengthening health systems by training doctors and nurses and building clinics.
Some developing countries have just one health worker per 1 000 people compared with one per 100 in Europe, it said.
Poor countries can also find it costly and time-consuming to deal with many different donors, it added.
The department did not mention any new funds for the scheme. The aid agency Oxfam gave a guarded welcome to the plan.
This initiative will only succeed if enough countries get behind it and if it mobilises additional aid to provide co-ordinated and expanded state health provision, Oxfam's director Barbara Stocking said.
Brown is promoting the new initiative as part of his efforts to kick-start the United Nations' Millennium Development Goals aimed at slashing extreme poverty by 2015.
A recent progress report found most of the Millennium Development Goals are far from being met.
At a June summit in Germany this year, world powers pledged to provide the finance needed to meet health care commitments made as part of the development goals.