Industria Venezolana de Aluminio, Venezuela's largest state aluminum smelter, didn't ship metal to Japan in December for the second time in five months as talks on a new supply contract stalled, according to Showa Denko K.K., the biggest Japanese shareholder in the Venezuelan firm.

Japanese companies are entitled to receive aluminum from Venalum, as the producer is known, as they own shares in the company, said Kyosuke Okano, general manager at the metal center of Showa Denko. The smelter also skipped an August shipment, Okano said in a Tokyo interview.

The missed deliveries forced Japanese processors to find alternative supplies and depleted stockpiles of the metal at the nation's ports to their lowest in at least 13 years. Venalum shipped 15,000 tons every two months to Japan, Asia's largest aluminum importer, under the previous supply deal.

"We want to agree on a contract with the producer as soon as possible," Okano said. Showa Denko, a metal fabricator, represents the Japanese shareholders in supply talks.

Maxwell Martinez, head of sales at Venalum in Ciudad Guayana, didn't respond to calls seeking comment.

Shipments were disrupted after Venalum asked Japanese companies to pay rising shipping costs. The smelter previously paid the freight charges.