PANAMA CITY, June 26 (Reuters) - Minera Panama, a subsidiary of Canada's First Quantum Minerals Ltd, said on Thursday it has shut down until further notice a $6.4 billion copper project in the country, citing labor disruptions.

Opposition to a new work schedule sought by Minera Panama during the project's construction phase sparked the conflict, the company said in a statement.

Since Sunday, nearby highways have been blocked by defiant workers as others have engaged in what Minera Panama describes as illegal work stoppages.

"The decision to close the site has been difficult and unfortunate," the company said in a statement, adding that boosting the project's efficiency is "absolutely necessary."

The company said workers are being evacuated and will be paid through June 28. It did not say when construction will resume, but added that it was "committed to the long-term success of the project."

Located about 75 miles (120 kilometers) west of the capital near the Caribbean coast, the project would aim to produce about 320,000 tonnes of copper, 100,000 ounces of gold and 1.8 million ounces of silver a year, the company's website said.

Shares of First Quantum Minerals rose 1.9 percent on Thursday to close at C$22.51 on the Toronto Stock Exchange.

(Reporting by Elida Moreno; Editing by Jan Paschal)