Unionized land-based workers of South Korea's largest shipper HMM Co. have voiced opposition to a company wage increase proposal, raising the possibility of its first strike, industry sources said Thursday.

After talks with its creditors, the company has put forward a wage negotiation proposal, including an 8 percent increase in wages, plus bonuses of 500 percent.

According to the sources, some 95 percent of unionized HMM longshore workers voted against the wage proposal.

Union members demand a 25 percent pay increase on top of a bonus amounting to 1,500 percent of their wages.

Labor and company representatives are scheduled to hold last-minute adjustment talks brokered by the National Labor Relations Commission later Thursday.

Should the adjustment negotiations fall through, the labor union is widely expected to vote on a labor dispute in the run-up to a strike.

Separately, HMM's labor union of seafarers is slated to hold another round of adjustment talks with management on a wage proposal after failing to iron out differences at the first meeting.

Industry sources said both sides are expected to try to jockey for position at their negotiations, but the possibility of a strike can't be ruled out, which could severely disrupt the country's exports.

It would be HMM's first labor action since the company's foundation in 1976.

The looming strike comes as HMM posted stellar performance in the second quarter of the year. Its operating profit rose 10 times from a year earlier to about 1.4 trillion won ($1.19 billion) in the April-June period on sales of some 2.9 trillion won.

HMM has received nearly 3.8 trillion won in public funds from the state-run Korea Development Bank and other government agencies in an effort to stay afloat. (Yonhap)