The European Union is refusing Japan's request in free-trade talks to allow the import of Japanese wine in bottles smaller than those commonly used in Europe, sources close to the matter said Friday.

Japan is asking the European Union to accept 720 ml bottles, which Japanese wineries typically use. But the European Union maintains such bottles would allow Japanese sellers to undercut prices, and demands Japanese wines be exported in 750 ml bottles widely used in Europe and other major markets.

The EU side expects Japanese producers to "move uniformly to the internationally practiced standard size," according to an EU internal document.

The Japanese government claims that use of different bottles would be a big burden to bear for Japanese wine producers, which are mostly small-scale enterprises, and that there is no discriminatory measure against EU wine bottles in Japan.

Japan and the European Union are also at odds over the bottling of shochu, a Japanese distilled liquor. Shochu is typically sold in 720 ml and 1.8 liter bottles.