Vancouver-based Eldorado Gold Corp.'s share price fell by as much as 37 per cent Thursday after a Turkish court ordered its Kisladag mine closed in a dispute about an environmental impact assessment.

Kisladag, in west-central Turkey, is set to become the largest gold mine in the country, yielding about 240,000 ounces a year at full production, the company says on its website.

Eldorado three-month chart

It describes the mine, operating since mid-2006, as "a 14-year, open-pit, heap-leach gold mine."

Heap leaching involves dissolving gold out of crushed ore with a chemical such as cyanide.

Eldorado's stock, which closed Wednesday at $7.22, fell as low as $4.55 Thursday on the Toronto Stock Exchange, temporarily wiping more than $900 million from the company's value.

It finished the day at $5.33, for a loss of $1.89.

A statement Thursday from Eldorado, which has other mines in Brazil and China, said Kisladag will close in about 30 days under the court order.

It believes the shutdown will be temporary but can't predict the timing, it said.

"The court decision is extremely disappointing for the company, Kisladag's employees, and families and local communities," Eldorado president Paul Wright said in the statement.

The company stressed it has all permits and licences needed to operate in Turkey, and the mine "continues to operate in accordance with the highest environmental and technical standards."

It won an initial court ruling confirming the legality and validity of  the environmental impact assessment, but a higher court has ordered the mine closed pending a decision on an appeal of that ruling, it said.