Commercial funding for Music for Youth has dropped two thirds in 10 years, from 64 per cent of total income in 1994, to 21 per cent in 2004.
Charitable donations have risen from 8 to 44 per cent in the same period.
But Larry Westland, executive director, says that this is not enough to cover expenses. "There's an awful lot of blather about corporate responsibility," he said. "But companies are only willing to put money in if they get tons of publicity."
Music for Youth recently lost two major sponsors, including Norwich Union, which had funded it for 31 years.
The charity organises a range of music events, including regional concerts, a national festival, and the annual Schools Prom. Mr Westland fears that, unless significant sponsorship is found this year, he will have to reduce the number of regional concerts.
Baroness Walmsley, the Liberal Democrat peer, recently drew attention to the problem in the House of Lords. She said: "I would have thought that a company wanting to demonstrate its corporate social responsibility would be happy to support talented children."