WELLINGTON - A New Zealand battery recycling plant is preparing to sue the New Zealand government for continuing to ship used lead acid batteries abroad, including to developing countries.

Wellington-based Exide Smelter is accusing the government of breaching its obligations under the Basel treaty on limiting international transport of hazardous wastes as well as its obligations under New Zealand's own Treaty of Waitangi between the government and the indigenous Maori tribes.

The company, which is the only battery recycling facility in New Zealand, said in a statement Monday that the government was obliged to favor New Zealand facilities where batteries could be disposed of or recycled in an environmentally sound way.

"We believe the government has failed to meet these legal obligations in exercising its discretion to grant export permits," said Exide's Australasian managing director John Cowpe.

It had invested millions into ensuring its smelter was environmentally sound, he said.

"However, we do not have any batteries to recycle because the government has granted permits to export nearly 100,000 tonnes to developing countries like the Philippines and to Korea since Jan 1, 2008," he said.

However, Environment Minister Nick Smith told the New Zealand Herald newspaper that while his preference was for the waste to be managed in New Zealand, the government needed to be satisfied Exide was run according to international best practice.

Exide's lawyers met with the Ministry of Economic Development Monday to discuss the litigation and will file proceedings with the High Court this week.