Private investment in UK arts increased by about £40 million in a two-year period, with donations skewed towards organisations in London.
The total investment from individuals, trusts and foundations has risen from £505 million in 2015/16 to £545 million in 2017/18, according to research by Arts Council England.
Money given to the arts in London dwarfs the totals donated elsewhere, with around £344 million being given to organisations in the capital, more than the rest of England combined.
The South West and Midlands have received just £36 million each, the South East £54 million and the North £74 million in private investment.
Arts Council England has said in its Private Investment In Culture Survey that this kind of investment is increasingly important as pressure is put on public funding.
From 2014/15 to last year, the proportion of public funding for the arts fell from 34% to 33%.
However, earned income from arts organisations has risen from 48% of the overall income to 52% during the same period.
Sir Nicholas Serota, chairman of Arts Council England, said: “Arts and culture in England depends on a successful mixed funding model, with private investment and earned income working alongside public investment.
“In a difficult time for public funding, many organisations have worked wonders by increasing earned income, but with an uncertain financial future it is necessary to diversify funding further.
“Private investment is crucial for the financial support it brings and the long-term relationship it helps build between the cultural sector and wider community.”
Of organisations surveyed by Arts Council England, just 10% of respondents expect an increase in local government funding, and only 6% expect growth in central government funding.
The lion’s share of current overall funding (54%) and private investment (66%) goes to London-based organisations.
Outside London, arts organisations are more dependent on trusts and foundations providing funding. Most private investment across England is made via individual donations.
Visual arts receive the most through private investment, with £148 million, followed by museums with £128 million and music with £96 million.