Christian Aid will withdraw its operations in six of the 48 countries it works in as part of a restructure.
The international development charity said its programmes in Jamaica, Peru, Rwanda, Sri Lanka, the Republic of Sudan and Tajikistan would gradually be withdrawn over the next year.
A spokeswoman said Christian Aid was in formal consultation with staff about the changes to roles and structure, which began this week. As part of the country exit strategies, 20 posts are proposed to be lost in the affected countries.
Across the entire international development department, 67 roles in total will go, including 20 vacant posts. But the spokeswoman said the restructure would create 66 new posts, although she said it was not yet clear where they would be.
The charity said that projects in Zambia, Sierra Leone, Kenya and India would receive significantly less funding from the charity, but its work would continue based on a model of investment that was intended to generate new income streams and alternative models of operation.
In India, different methods of working and fundraising that involve the private sector were being introduced, the spokeswoman said.
Christian Aid said the changes were not being made because of financial troubles, and any money saved would be invested in other international programmes.
In 2011/12, the charity’s income was £95.5m, up slightly from £95m in 2010/11.
According to the annual report, the charity gave grants totalling £1.9m in Jamaica, Peru, Rwanda, Sri Lanka and Tajikistan in 2011/12. It also gave a further £1m in Sudan and South Sudan. The charity will continue its work in South Sudan, which became an independent state in 2011, but not the Republic of Sudan.
Grants given in Zambia, Sierra Leone, Kenya and India in 2011/12 totalled £9.3m.
Paul Valentin, international director at Christian Aid, said the charity had held a review of its operations.
"The review looked at how we can make use of our core resources – funds, people and time – in a way that will achieve major, deep and lasting change," he said.
"Additional investment in other programmes, in particular in the DRC, South Sudan, Myanmar, Bangladesh, Bolivia and Central America, will make a huge difference and enhance our efforts to challenge the structural causes of poverty.
"The process identified countries where opportunities to have a significant impact have become increasingly limited. In some, the cost of staffing an office is proportionally more than the benefits it brings."