JAKARTA, May 8 (Reuters) - Indonesia will extend copper

concentrate export permits for Freeport Indonesia and Amman

Mineral Nusa Tenggara, President Joko Widodo told reporters on

Wednesday, adding that details of the extensions were still

being worked out.

Both Freeport Indonesia and Amman are building

copper smelters expected to start operation in June. But the

companies have said the new smelters would need months to ramp

up capacity to absorb their copper concentrate output.

The current permits are set to expire on May 31.

"I suppose, with the completion of the smelters, it shows

their strong desire to start downstreaming in the country," said

Jokowi, as the president is popularly known.

Speaking of the companies' plans while referring to his

policy priority of having more mineral processing take place in

Indonesia, he added that their permits would be extended but the

government was still calculating the details.

An Amman spokesperson said the permit extension would help

continuation of the company's mining and expansion projects.

Freeport Indonesia did not immediately respond to a request

for comment about the extension.

Freeport is preparing to ship as much as 900,000 metric tons

of copper concentrate, starting in June, from its Grasberg mine

after positive talks with Indonesia to extend its export

licence, two sources said this week.