On September 5, there was a report of complaints against Banpu's Trubaindo mine for allegedly discharging wastewater into a river. Since then, the company's market capitalisation fell from Bt38.5 billion to Bt36.4 billion after its share price tumbled from Bt142 on September 5 to Bt134 yesterday.

Indonesian authorities have launched an investigation into the complaints and it should be wrapped up within one or two weeks, according to Chanin Vongkusolkit, Banpu's president. "If the mine has encountered problems as reported, the company's board of directors will convene and discuss [possible] solutions," he said. Banpu yesterday flew a group of Thai reporters to Indonesia to see its mining operations there first hand.

Despite the problem, Chanin said he was confident that the company's 2006 revenue target of Bt30 billion would not be affected. Banpu has already achieved its first-half goal and its production capacity has been on the rise. In the first half, the company reported revenue of Bt15.7 billion and a net profit of Bt1.55 billion.

Banpu ventured into Indonesia in 1990, where coal resources are abundant. Over the past decade, the company has developed a significant presence in the country, ranking as the fourth-largest Indonesian coal producer, with full production capacity of 19.4 million tonnes per year. It has four concessions, at Indominco, Kitadin, Jorong, and Trubaindo.

Siam City Securities said if the Trubaindo mine was closed, it could put more pressure on the company's share price forcing it down to the Bt121-Bt131 range.

The broker recommended that investors buy the stock on the belief that the company's share price could rise to Bt155.70 this year, based on its revenue structure.

Coal accounts for 53 per cent of Banpu's revenue, power generation 24 per cent, and other investments account for the rest.