GM Korea Co. said Tuesday that it has failed to produce any substantial progress in wage negotiations with union leaders as the shutdown of one of its four car assembly plants in South Korea looms.

"We explained our stance to the management," union spokesman Dang Sung-geun said after what he described as "a get-acquainted meeting" at the carmaker's main Bupyeong plant, just west of Seoul.

Last week, unionized workers made conditional offers to accept the wage freeze and no bonuses demanded by the carmaker's parent firm, General Motors Co., in joint efforts to turn the loss-making Korean unit around.

On Tuesday, the union pressed management to spell out a concrete roadmap on the allocation of new vehicles at the next round of negotiations. The union also renewed its demand that the company withdraw its plan to shut down the plant in Gunsan, about 270 kilometers southwest of Seoul.

GM Korea's 13,000-member union has asked the Detroit carmaker to convert the outstanding debt worth US$2.7 billion it extended to its Korean unit into equity and present a detailed plan to allocate new vehicles to its South Korean plants.

GM Korea's management has already explained its stance to the union in previous meetings.

"The company will carefully review the union's demands and discuss them in negotiations," company spokesman Park Hae-ho said.

The sides are set to hold their sixth round of talks on Wednesday.

Also Tuesday, GM Korea said in a regulatory filing that it has replaced five non-standing directors.

GM announced in February it will close its plant in Gunsan by May, although it claimed it can inject fresh capital into its Korean unit if the union accepts a wage freeze and no bonuses along with the suspension of certain work benefits.

The auto giant already said it can convert into equity all of the outstanding debt and fund its portion of a planned $2.8 billion investment in products and facilities.

The Detroit carmaker has been pressing the state-run Korea Development Bank, the second-biggest shareholder in GM Korea with a stake of 17 percent, to extend a financial helping hand to put the Korean unit back on track.

The KDB has said it could provide short-term loans to GM Korea to help stay afloat during the ongoing due diligence being carried out on the carmaker.

KDB Chairman and CEO Lee Dong-gull has said the KDB may invest new money in GM Korea if GM's future plans in its Korean unit are viable and sustainable.

PricewaterhouseCoopers began its due diligence process on GM's Korean unit on behalf of the KDB, with an aim to complete the review by the end of April. GM said it would face a cash crisis during the first quarter if no new funding comes from GM Korea shareholders. (Yonhap)