The BBC Trust has approved plans to run adverts on on the Berlin FM frequency of BBC Radio's World Service in a trial lasting a year.
The advertising will be the first on BBC Radio broadcasts. Adverts will also be put on the Service's Arabic, Russian and Spanish websites.
In 2010 the British government reduced the World Service's annual budget by 16% and said the Foreign Office would no longer fund it from 2014.
The service has to generate £3 million from commercial activities by 2013 - 2014.
The World Service began broadcasting in 1932.