SEOUL (REUTERS) - Asian trade powerhouse South Korea took a step closer on Friday to joining 12-nation talks aimed at slashing trade barriers between nations making up about 40 per cent of the world economy.

The world's seventh-largest exporter said after a meeting of top economic officials that it would soon enter negotiations with the United States, Japan, Canada and nine others already in the group.

"(The government) expects participation in the TPP to help (the country) secure a big market spanning over the Asia-Pacific region and to allow competition with the other member countries on an equal footing," it said in a statement.

The Trans-Pacific Partnership trade pact, which would also include Australia, Brunei, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam, would establish a free-trade bloc across the region.

The negotiations, which have run for three years, have been mired in controversy over a lack of transparency and slowed by the conflicting interests of the negotiating countries, US lawmakers and advocacy groups.

South Korea, the world's 15th-largest economy, has already signed bilateral free-trade pacts with both the United States and the European Union and has until now said it would focus on pending free-trade talks, including those with China and Australia, before deciding on the TPP.

In its statement, the government said it would make a final decision on whether to formally join the deal based on the outcome of talks with the member countries.