Indonesia smelter workers block Koba tin shipment

PANGKAL PINANG, Indonesia Nov 25 (Reuters) - Hundreds of smelter workers on Indonesia's Bangka island thwarted an attempt by tin producer PT Koba Tin to export 400 tonnes of ingot to Singapore on Friday, as they sought to enforce a self-imposed industry shipping stoppage.

Smelters in the region stopped shipments from Oct. 1 in an effort to push benchmark tin prices above $23,000 a tonne. At the time, analysts were unconvinced that the stoppage would hold firm.

"This is a lesson to a company that is breaking the deal," added Johan Murod, secretary at the Indonesia Tin Association (ITA). "Don't try to export as it will push down the price ... any company that is trying to export will be intercepted."

The ITA said earlier this week that it would use "people power" to stop unlisted PT Koba Tin, a joint venture between Malaysia Smelting Corporation and PT Timah, from fulfilling contracts agreed before the export stoppage came into effect.

"We forgot about the moratorium made with the tin association," said Miswanto, a logistics manager at PT Koba Tin, after the shipment was blocked at a port. "Koba Tin decided to cancel the shipment to Singapore."

The ITA, an industry group of 28 smelters from the world's top refined tin exporting country, has also said it would ask PT Timah, the world's largest integrated miner, to halt all shipments as it tries to plug leaks in its eight-week old ingot export stoppage.

PT Timah's exports contributed to a surprise rise in monthly export data for October, the ITA said earlier this month, and analysts say stricter enforcement would be needed to achieve higher prices.

Tin traded at $20,100 a tonne on the London Metal Exchange by 1038 GMT. Prices for the metal, mainly used in solders for electronics, have fallen since a record high above $33,000 a tonne in April. (Reporting by Dwi Sadmoko; writing by Michael Taylor; Editing by Neil Chatterjee)