Oxfam is expected to cut 125 jobs in the UK as part of a major restructure of its operations aimed at saving £7.5m over the next year.
The charity said that the majority of the jobs would go in its Oxford headquarters, but some of its regional offices – which are in London, Manchester, Bristol and Birmingham – might close.
Areas affected by the changes include human resources, finance, business support and campaigns and policy, the charity said.
Oxfam employs 1,900 staff in the UK, although about 700 of these are shop managers who will not be affected by the job losses, a spokeswoman for the charity said.
Oxfam’s income fell by £17.6m to £367.9m in the year to March 2013, according to its latest accounts.
The restructure will result in the charity, which works in 94 countries, focusing its resources on fewer places.
Oxfam said that the changes would improve its ability to influence governments and institutions in developing countries and promote the rights of poor women.
"The changes will be implemented in two stages," a statement from the charity said. "Initially there will be reform of a number of services, including human resources, finance, business support, and campaigns and policy at the Oxford-based headquarters.
"This will enable Oxfam to balance its budget and, in due course, provide additional funds to invest in programmes. The proposed plan is expected to result in the loss of 125 posts in the UK and the closure of some English regional offices."
The second stage of the restructure will take place from 2015, when the charity will make the changes to its international programmes, working with the 16 other Oxfams around the world.
The spokeswoman said the charity hoped to make savings of a further £10m from the second stage.
The charity said that it would make "every effort to keep the number of redundancies to a minimum" and help people find other work.
Mark Goldring, chief executive of Oxfam, said: "It is imperative that we have an Oxfam that lives within its means and is relevant to 21st-century needs. Advances in technology mean we no longer need as much support in our head office. Instead, our resources will be focused on the regions, where we carry out the majority of our work.
"This will mean we can deliver the most effective and efficient support to the millions of people who go to sleep hungry each night."