South Korea deployed hundreds of troops to help at subway stations yesterday during a strike while union action widened to a car plant and activists at a major oil refiner defied arrest and deadlines to return to work.

The wave of strikes pose a serious test for President Roh Moo-hyun, a former labour lawyer who has previously been criticised by employers and foreign investors for being too soft on militant labour unions. The widening strike action comes when the economy, Asia?s third-largest, is struggling with weak domestic spending and depressed business investment.

Ahn Chang-ho, deputy chief for public security at the state prosecution office, said it planned to file for court warrants later in the day for the arrest of five union leaders at LG-Caltex Oil Corp for organising the strike. Another official denied that prosecutors had come under pressure to act against the strikes, which the government has called illegal. ?It?s not true that our decision is being influenced by the presidential office, but there are procedures we have to take before we actually arrest someone,? said the official. More than 850 troops were deployed at stations to help after some 65 percent of unionised subway workers in Seoul and three other cities took their strike into a second day, officials said.

Workers ignored a 9:00 a.m. (0000 GMT) deadline set by one of the two subway operators in Seoul to return to work, government officials said. The other operator set an 11:00 a.m. deadline. And most strikers did not return to work at the huge oil refinery complex run by LG-Caltex Oil Corp. by an 8:00 a.m. deadline set by management, company officials said.

LG-Caltex, a 50:50 joint venture set up in 1967 between South Korea?s LG Group and ChevronTexaco Corp., said only 32 union members had turned up, and 802 were still absent. Apparently hit by the labour unrest, the company delayed a $300 million bond offering ?until further notice?, a market source said. Company officials could not confirm the delay.

The company said about a third of plants had resumed normal operations and it now aimed to bring its refinery back to full operation in a week or two. It normally produces 650 000 barrels per day and accounts for a quarter of domestic refining capacity.

The industrial unrest spread into the automobile sector when workers made good on a threat to strike at Ssangyong Motor Co., a sports utility vehicle maker, the company said. The company?s 5 600 member union had staged a partial strike since July 12 to push for higher wages and job security because of a planned sale of the company to a new owner.

Seeking to turn public opinion against the subway strike in a country that traditionally sees a wave of industrial unrest in the summer, operators in Seoul placed advertisements in several newspapers criticising the striking workers. ?Is it fair for an employee working 19 days a month and receiving 45 million won ($38 700) a year to stage a strike?? read the advertisement. ?Does the company have to accept the union?s demand the workforce be increased by 34 percent?? Union officials were not immediately available to comment.

The subway strikers appeared unmoved after warnings by operators in Seoul, Pusan, Taegu and Inchon ? all owned by city governments ? that they would face punishment or dismissal if they failed to return to work by Thursday morning. Prosecutors warned unions on Wednesday that leaders of the subway strike could face arrest and that they may detain organisers of the walkout at LG-Caltex Oil Corp.

Subway managers have already suspended dozens of union leaders for organising the walkout. The strike was launched after management rejected union demands for wage increases of up to 10 percent and the recruitment of more workers after the work week was cut to five days from six from this month.

About 10 000 former drivers, soldiers and public workers have been drafted in to try to keep the subway running, but trains were now running at much wider intervals than usual.

Yoo CHOONSIK Park SUNG-WOO