Three-way negotiations among South Korea, Japan and China for a free trade agreement came to an end Wednesday with some progress but not a significant breakthrough, Seoul officials said.

The chief negotiators from the three countries held the latest round of talks in Seoul that began Tuesday in an effort to iron out differences over the proposed trade deal.

"We have made headway on some issues, but the talks continued to move slowly," said Kim Hak-do, Seoul's chief negotiator to the talks, the seventh of their kind since the first round in March 2013.

Officials here said the countries have been unable to move forward on the issue of market liberalization for products.

"The sides only confirmed their differences on the level of market opening as they again laid out their own principles," a Ministry of Trade, Industry and Energy official said, asking not to be identified.

The three countries have said they will work to conclude the negotiations before the end of next year.

Efforts to move the talks forward included separating working-level talks from a head delegates' meeting, a move aimed at enabling detailed, in-depth discussions at the working level while leaving sensitive and political decisions to chief negotiators.

This week's meeting of chief negotiators followed working-level talks held in Seoul from April 13-17.

Officials from South Korea's trade ministry said the next round of the three-way talks will be held in China in July.

"They will continue to hold in-between sessions followed by working-level talks in the near future," an official said.

The proposed FTA, if signed, will become one of the most significant free trade pacts ever signed in the region as it will link three of Asia's four largest economies.

The three countries are also taking part in negotiations for a separate regional FTA, known as the Regional Comprehensive Economic Partnership, that currently involves 13 other countries, including all 10 member countries of the Association of Southeast Asian Nations.

South Korea and China have concluded separate negotiations for a bilateral FTA, which is expected to be officially signed in the near future.

Seoul and Tokyo have also held four rounds of talks for a bilateral FTA, but the talks have been suspended since the latest round in November 2004. (Yonhap)