* Thousands of workers to extend strike -union
* Company says Grasberg copper mine is running as normal
* Freeport negotiating new mining permit with govt (Recasts on Freeport Indonesia comment, adds background)
JAKARTA, June 22 (Reuters) - Operations at the world's No.2 copper mine in Indonesia are "running as normal", a spokesman for the local unit of Freeport-McMoRan Inc said, despite thousands of workers extending a strike for another month.
Riza Pratama said in a text message on Thursday that "around 25,000 workers and contractors" continued to work at the Grasberg mine, a key supplier to buyers including top metals consumer China.
That came after Freeport Indonesia union industrial relations officer Tri Puspital told Reuters on Wednesday that 6,000 workers would remain on strike.
Workers started their strike in May after Freeport laid off around 10 percent of its 32,000 workforce while it negotiates a new mining permit with the government.
Freeport resumed exports of copper concentrate in April after a 15-week outage related to the negotiations with Jakarta.
Earlier this month, Freeport's chief financial officer said the company was on track to reach an agreement with the government.
Reporting by Bernadette Christina Munthe and Fransiska Nangoy; Editing by Joseph Radford