Universities try to cash in on discoveries — gene splicing, brain chemistry, computer-chip design — but the great majority of them fail to turn their research into a source of income, according to a new study from the Brookings Institution.

Research universities have “technology transfer” offices that make thousands of business deals annually for the use of their patents. But in any given year, at about seven of eight universities, the resulting revenue funneled into university budgets is not even enough to cover the cost of running that office, said the study’s author, Walter D. Valdivia.

Universities make money from patents primarily by licensing them to outside companies, which turn them into commercial products. Mr. Valdivia said the universities needed to become more aggressive about nurturing new businesses, encouraging professors to start new companies based on the patents and making licensing deals that would give them an ownership stake in corporations, not just a share of the royalties.

A 1980 federal law gave universities ownership of patents arising from federally funded research, and the results have generally been seen as a boon to universities. They make more than 4,000 patent licensing agreements annually and collect about $2 billion a year in licensing revenue, according to surveys by the Association of University Technology Managers.