Posco's labor union members gather to commemorate the launch of the labor union's strategic task force, in Gwangyang, South Jeolla Province, Sept. 6. (Yonhap)

Posco is facing a possible labor strike for the first time in its 55-year history as it failed to bargain with its labor union for the second time since wage negotiations began in August.

Wage talks between Posco's management and the union fell through late Thursday afternoon as the two sides failed to narrow their differences, according to the company.

As a result, Posco's labor union said it will apply for a mediation process led by the National Labor Relations Commission, and hold an inside vote to decide whether or not to initiate a walkout.

According to Posco, during the negotiation, the company offered an increase of 162,000 won ($120) in base salary, along with providing 6 million won in benefits -- which included four million won in stock, 1.5 million won in cash and 500,000 won in gift certificates issued by local governments.

The company added that it offered the union members a proposal to form a joint labor-management task force, in a bid to continuously discuss ways to improve Posco's incentive system, as well as the corporate welfare system, with the labor union.

Regarding the company's offers, the labor union said the terms fell short of its demands.

The union's requests currently consist of a total of 86 demands, including a 13.1 percent increase in base salary, the provision of 100 Posco treasury stocks for each employee, bonuses worth three times each individuals' salaries, and 2 billion won in support for union members' activities.

In regards to the labor union's requests, Posco said the company currently cannot fulfill their demands as it recently suffered a 50 percent drop in operating profits, and some 2 trillion won in losses due to the effects of typhoon Hinnamor destroying its major facilities at Pohang.

"If the company adheres to all of the demands, it is expected to cost some 1.6 trillion won," a Posco official said.

"However, considering the possible effects (strikes at Posco) could incur in Korea and the local economy, we have prepared the optimal plan to sustain a culture of trust and harmony. We are putting our best efforts into reaching an agreement," he added.

Meanwhile, the labor union explained to Yonhap News that Posco executives were currently reaping personal gains by receiving hundreds of millions of won in treasury stocks through the stock grant system. Also known as employee grants, stock grants give the employees the option to purchase shares of common stock at an agreed-upon price.

"Regarding this, union members also need to have their base salaries raised and treasury stocks offered. However, the company's current proposal does not sufficiently address that," an official from Posco's labor union told Yonhap News.

Posco's labor union could not be reached for comment as of press time.

The second official decision to cease negotiations comes after both parties declared its first cessation of talks after failing to reach an agreement in August. On Sept. 21, both parties resumed discussions, and have since been holding roundtable talks.