Ridwan Max Sijabat and Andi Hajramurni, Jakarta/Makassar – Thousands of workers of publicly listed PT International Nickel Indonesia (Inco) entered the sixth day of their strike in Soroako, South Sulawesi, on Tuesday.

The workers were demanding a higher share in profits and promotions for local workers, threatening the country's largest nickel producer's operations.

Chairman of the Inco Workers Union Andi Karman said the workers decided to strike after collective bargaining with the management since last May failed to produce a resolution.

"The industrial strike is our last resort; to pressure the management into bowing down to our demands and it will continue until our demands are fulfilled," he told The Jakarta Post by telephone.

Andi said workers had the right to receive bigger bonuses following the company's high profit in this year's first two quarters, which was in line with rising nickel prices on the world market.

"We have demanded a 50-percent bonus increase in the first semester from the current 25 percent," he said.

He added the union had also been disappointed with the management's decision to recruit new management staff, instead of promoting field workers who had worked with the company for more than ten years.

Inco president director Arief Siregar was not available for comment. However, Inco spokesman Jannus Siahaan said his company could not meet the protesters' demands because they were not regulated in the company's collective labor agreement and the 2003 Labor Law.

"The management has shown its strong commitment to profit-sharing by improving workers' welfare, but it is impossible for the management to negotiate matters that are not regulated either in the Labor Law nor the collective labor agreement," he said.

He said the strike had affected the company's production but declined to specify by how much.

On a regular day, the company's nickel production can reach 2.5 million pounds a week.

Director General for industrial relations and social security programs at the Manpower and Transmigration Ministry, Myra Maria Hanartani, criticized the prolonged strike, saying workers and the management should go to the negotiating table to solve the industrial dispute.

She said the government could not interfere in the company's internal affairs since the management had not violated the Labor Law and the collective labor agreement.

She said the workers should initiate a dialogue, rather than continue to strike, as the company had complied with all regulations.

Chairman of the Indonesian Mining Association (Perhapi), Irwandy Arif, concurred and said the dispute could be a bad precedence for other mining companies if Inco's management met the workers' demands.

"Employers have the obligation to respect their workers' rights but workers should be aware of what their rights are, as regulated by the law and the collective labor agreement," he said, adding workers wouldn't get a cut in their monthly salaries if the management suffered losses.