About 12 percent of corporate lendings by Korea's two government-owned policy lenders were extended to marginal large companies as of 2014, a report showed Monday, amid rising public calls for drastic corporate restructuring.

A company failing to earn enough operating income to cover its interest expenses for three consecutive years is defined as marginal by the Bank of Korea.

The Korea Development Bank (KDB) and the Korea Export-Import Bank (Exim Bank) provided a combined 82 trillion won ($7.12 billion) to domestic companies last year, up from 34 trillion won in 2008, according to the report by the state-run Korea Development Institute (KDI).

The portion of large companies in the policy lenders' lending surged to an all-time high of 47.5 percent in 2014, compared with 41.6 percent tallied in 2008, when the global financial crisis started to sweep the world.

The KDI report noted that the share of marginal large companies in the two lenders' outstanding corporate loans rose to 12.4 percent in 2014 from 1.9 percent in 2009.

Separate industry data showed that nearly 9 percent of Korea's top 500 companies are unprofitable and highly indebted firms that can't even pay interest on loans with operating profit.

The highly indebted companies are subject to the government-led restructuring plan as part of efforts to prevent any fallout on the economy from their sudden collapse amid growing economic uncertainties at home and abroad, including a looming U.S. interest hike and sluggish domestic demand.

The government said the restructuring project may cause the policy lenders to shoulder massive financial burdens.

"Private financial institutions have reduced lending to the indebted corporations due to higher risks and size," a finance ministry official said. "The KDB and Exim Bank have to expand their capital to carry out the restructuring project."

Finance Minister Yoo Il-ho earlier said he is mulling shoring up the capital of the state lenders to help them secure enough money to lead corporate restructuring.

Experts demanded the government make a quick decision to maximize the effect of the restructuring efforts.

"The government's determination is important as the policy lenders are the major shareholders and creditors of many financially troubled shipbuilders," said Nam Chang-woo, a senior economist at the KDI. "It has to consider asset disposal or other measures." (Yonhap)