UPDATE 1-Century mine zinc port stockpile to run out

* Century zinc mine concentrate port stockpile running out

* Customers looking to buy concentrate elsewhere (Adds details, quotes)

SYDNEY, Nov 17 - Australia's Century zinc mine will run out of concentrate at its shipping port later on Tuesday, forcing buyers to look for alternative supply sources, a spokeswoman for the mine said.

Shipments of concentrate from the world's second-largest zinc mine to the port of Karumba in eastern Australia, where it is stored before being loaded onto ships, were halted in October due to a break in the pipeline used to transport the material.

"We have nearly completed shipments of all the current stocks in the storage shed in Karumba and we expect to complete that today," said Sally Cox, a spokeswoman for the mine's owner, China's Minmetals.

"So our customers are sourcing alternative concentrate."

Cox declined to comment on whether a declaration of force majeure had been made to protect the company from liabilities under its supply obligations to customers.

The 304-kilometre pipeline carrying wet concentrate from the world's second-largest zinc mine to a storage shed in the port burst on Oct. 5.

Cox said Minmetals expect its customers to resume purchasing concentrate from the mine once the port's stockpile is replenished, noting major buyers in Europe, including Belgium's Nyrstar <NYR.BR> rely on the mine's low iron-bearing material to adhere to environmental rules for smelting.

Mining was continuing, with ore being stored at the mine site, Cox said.

Installation of a bypass pipe section was expected to be completed by early next week at the latest, enabling tests using water through the pipeline to start prior to clearing the pipeline to resume shipments, Cox said.

The port's stockpile had stood at 10,000 tonnes on Nov 11, down from 70,000 tonnes prior to the incident.

Trading sources said the disruption could have an immediate effect on buyers because the stockpile, which had swelled to 100,000 tonnes earlier this year, was already being reduced due to concerns material was contaminating a nearby town.

The Century mine yields about 500,000 tonnes of zinc, a third of Australia's total production, from 1 million tonnes of concentrate annually.

The Australian Bureau of Agricultural and Resource Economics estimates total world consumption of zinc at 10.74 million tonnes this year.