The Joseph Rowntree Charitable Trust will make an extra £3m in grants available each year as part of a review of the trust’s work.
The increase means the JRCT will make £10m worth of grants available every year for the next decade.
The trust said that the increase in funding was part of its 10-yearly review of its work and was aimed at meeting increased demand on the JRCT’s grants programme.
Work to increase the number of grants awarded outside London will be a feature of the JRCT’s work over the next 10 years in a drive to increase the geographical diversity of grant funding in the UK.
Long, larger or core grants will be made available where suitable, the JRCT said.
Annual fixed-grant spend at the trust will also increase every year in line with inflation.
Further details for grant applicants and recipients will be announced later this year and the changes are expected be in force before the end of 2019.
Nick Perks, trust secretary at the JRCT, said: "We’re pleased to be able to increase our grant funding, which reaffirms our commitment to engage in philanthropy that supports people who address the root causes of conflict and injustice.
"We have decided to make more grants across the UK in recognition of the importance of devolved nations and regions and that systemic change requires many voices and experiences.
"We want to be an open and responsive funder and we know that more core or unrestricted grants are what many charities want and could greatly benefit from."