Bolivia says may revoke Glencore mine license

* State miner says government looking at revoking concession

* Colquiri tin, zinc project halted by miners' protest

LA PAZ, June 11 (Reuters) - Bolivia's leftist government said on Monday it could strip global commodities giant Glencore of an operating license at a tin and zinc mine that has been paralyzed by a workers protest for the last 12 days.

President Evo Morales has steadily increased state control over natural resources and utility services in the mineral- and natural gas-rich country and his government is working on a shake-up of mining contracts.

The mineworkers' union at Glencore's Colquiri mine wants the concession to be revoked, but four independent mining cooperatives that exploit the same site say it should remain in place, state mining company Comibol said.

Colquiri is one of three mines operated by Glencore's Sinchi Wayra subsidiary in the Andean country. It has been at a standstill since May 30 when it was occupied by miners belonging to independent cooperatives who want to be granted new areas to mine.

"This wouldn't be a nationalization in the classic sense of the term because the site already belongs to Comibol. It's being exploited under contract," head of state mining firm Hector Cordova told reporters.

"It would simply be a matter of annulling this contract and Comibol would resume operations it carried out until 2000," he said, adding that the concession could be revoked by decree as soon as this week.

No one could be reached to comment at Sinchi Wayra, which exported minerals worth over $300 million last year.

Albino Garcia, head of the powerful Federation of Mining Cooperatives, threatened to "occupy every private mine in the country if the government nationalizes Colquiri."

Colquiri produced 2,000 tonnes of tin concentrate last year, according to Comibol data.