BHUBANESWAR, Jan. 12 -- India's state-run National Aluminium Co Ltd (NALCO) <NALU.BO) issued a tender on Monday to export 6,000 tonnes of aluminium ingots, a source in the company said.

Bids have to be submitted by Jan. 18, and the metal will be shipped in six batches of 1,000 tonnes each month from February to July, said the source, who has direct knowledge of the tender process but can not be identified due to company policy.

NALCO, whose tenders serve as an international benchmark, last sold 2,500 tonnes of primary aluminium ingots last week to European trading firm Trafigura at a premium of $78.25 a tonne over the LME cash price on a CIF basis, the source had said.