Armenia's state radio has refused to extend a contract with the US government-funded Radio Free Europe/Radio Liberty (RFE/RL).
With elections early next year, the move on Wednesday has prompted fears of a clampdown on independent media in the former Soviet state.
The US Broadcasting Board of Governors (BBG), the agency responsible for Radio Liberty and other US government-sponsored international broadcasting, said in a statement that there was "no economic or other legitimate justification" for the contract to end.
"Armenians go to the polls in eight months to choose their next president, and therefore it is particularly important that RFE/RL's broadcasts ... reach the largest possible audience," the BBG said.
Radio Liberty is the only foreign broadcaster that relies on state radio frequencies.
Earlier in July, a small number of demonstrators protested against proposed amendments to Armenia's media law that would prevent programmes produced by foreign companies from being aired on state channels.
Radio Liberty would be the only broadcaster effected by such legislation, but government officials at the time denied that was their aim.
Ultimately, the amendments were not adopted by parliament. Instead, Radio Liberty is being taken off the air after contract negotiations broke down.
The government has argued that Armenia's state television and radio are publicly funded and should not take up commercial projects.
Radio Liberty may still air its Armenian broadcasts on private radio, though these would reach a smaller audience.
Al Jazeera and agencies
Güncelleme Tarihi: 26 Temmuz 2007, 19:35