Sri Lankan exports would suffer over 10 percent slump in volume as a result of losing a European Union (EU) trade concession, industry sources said on Thursday.

"There will be a loss of 12 to 15 percent," A. Sukumaran, the chief of the Joint Apparel Exports Association told reporters here Thursday.

Sukumaran said the exports affected by the loss of the EU's General Systems Preferences (GSP+) facility amounts to around 500 million U.S. dollars.

The EU would withdraw the facility which provided Sri Lankan exports preferred tariff treatment from Aug. 15 this year.

The EU linked Sri Lanka's honoring of 15 conditions to do with civil and political rights if the EU were to extend the facility which Sri Lanka has enjoyed since 2005.

The Sri Lankan government has rejected the conditions claiming they impinge on the island's sovereignty.