Acevo, the membership body for charity chief executives, saw its turnover fall by almost a third in 2011/12, according to its latest annual accounts.
Income in the year to March 2012 was £2.15m, compared with £3.16m in the previous year.
Almost all of the loss was accounted for by the removal of funding for policy and advocacy work, including the loss of £798,000 from the government-funded infrastructure body Capacitybuilders, which closed in 2011.
Acevo also recorded a larger-than-expected deficit of £169,000, which the charity said was largely due to below-budget returns from events and membership. The charity had projected a loss of £16,000.
Acevo’s membership fell by 5 per cent to 1,510 members and attendance at its events dropped by 21 per cent to 4,164 people. The number of events it held fell by 35 per cent.
In its annual report, Acevo described the past year as "challenging".
"We saw significant reductions in budgeted income, largely driven by events and membership," the report says. "We are fortunate to have strong reserves to support the organisation’s development through this changing climate."
The accounts say its free reserves stood at £538,000 at the end of March.
Acevo did see growth in the trading of its subsidiary, Acevo Solutions, which saw its turnover rise by 60 per cent to £327,000 a year.