By Fabian Cambero
SANTIAGO, April 27 (Reuters) - BHP Billiton BLT.L BHP.AX is advancing with the sale of its small Cerro Colorado copper mine in Chile and there are a number of interested parties, although finalizing the deal will likely take some months, the mine's union said on Thursday.
BHP management updated union leaders on the planned sale of the mine this week, ahead of planned visits to the deposit by potential buyers, union leader Marcelo Franco said in an interview.
BHP declined to comment.
Cerro Colorado produced 74,000 tonnes of copper last year out of top exporter Chile's total 5.5 million. Located in the extreme north of the country's copper belt, it has permission to operate until 2023 but that could be extended.
"(The sale) is already pretty well advanced, but they said it could last some months," said Franco.
Franco said he did not know the identity of the interested parties. Traders have mentioned Chile's Empresas Copec SA COP.SN , a conglomerate that has voiced interest in diversifying into copper, and Canadian companies such as Lundin Mining Corp LUN.TO , as possible buyers.
He said the union had a positive attitude toward a future deal as workers' benefits were legally assured and it felt BHP was more focused on its larger Chilean assets, Spence and Escondida - the world's biggest copper mine.