The agreement, first signed in 2000, allows nearly all exports from the Western Balkans to enter the EU without customs duties or limits in quantity.
Albania, Bosnia, Croatia, Kosovo, Macedonia, Montenegro and Serbia all benefit from the pact.
"The aim of this proposal is to ensure that Western Balkan economies continue to benefit from an unlimited duty free access to the EU market for nearly all products originating in these countries and territories," the EC said in a statement.
Together with the bilateral agreements in place, these trade preferences support economic integration with the EU and hence foster political stability and economic progress in the entire region, the EC said.
The agreement, previously renewed in 2005, is due to expire in December, 2010. The new deal would come into force in January, though it must first be approved by EU ministers and the European Parliament.
Stopping the trade preferences "risks having negative consequences on the overall economic performances of Western Balkans, with repercussions on their domestic reform processes," the EC said.
The EU is the region's top trading partner, exporting 32.5 billion euros of goods to the Western Balkans in 2008 and importing 14 billion euros' worth in the same period.
Only wine, baby beef and certain fisheries products face preferential tariff quotas under the pact.
Both communities in Kosovo blame politics for the trial of Fatmir Limaj - though from diametrically opposing points of view.