Turnover of South Korea's over-the-counter stock market has been surging this year thanks to growing investor attention amid ultra-low interest rates, a market tracker said Friday.

The value of transactions on the K-OTC nearly doubled in six months, soaring to 15.7 billion won ($14.1 million) in July from 7.6 billion won in January, according to financial information provider FnGuide. The turnover reached 15.2 billion won in the first 24 days of this month.

The Korea Financial Investment Association operates the OTC market where unlisted blue chips are traded. In August 2014, KOFIA revamped the previous OTC bourse to liven up trading.

KOFIA attributed the surge in turnover mainly to a long period of low interest rates.

"An increasing number of investors are getting interested in unlisted stocks as it is difficult to find proper investment products amid the worsening of a low-rate trend," said Han Jae-young, a senior KOFIA official.

The interest is also based on expectations that their investments may get listed on the country's main and secondary bourses or the Korea New Exchange for venture firms and startups sometime in the future, giving them huge profits.

So far, eight companies have been promoted to the three bourses, with Samsung SDS Co., a key IT unit of South Korea's top conglomerate Samsung Group, and three other companies getting listed on the main KOSPI market.

In order to further invigorate trading on the K-OTC, KOFIA said it has called on the government to reduce taxes on capital gains. Currently, K-OTC investors are required to pay up to 20 percent of their capital gains in taxes.

"Investors in shares traded on the Kospi and secondary Kosdaq markets are exempt from the capital gains tax," Han said. "The same rule should be applied to the K-OTC to revitalize its trading." (Yonhap)