July 30 (Reuters) - Orocobre Ltd said on Thursday quarterly production fell 27% at its flagship Olaroz mine, and the Australian lithium miner brought forward a planned maintenance for the Argentinian project due to a spike in COVID-19 cases at nearby operations.

Production from the Olaroz plant for the June quarter came in at 2,732 tonnes, down from 3,455 tonnes last year, due to a temporary shutdown put in place following coronavirus-related restrictions.

While operations have continued with a limited workforce, new COVID-19 infections have emerged at nearby operations and in some local communities, the Brisbane-based company said, adding that average prices for its lithium carbonate dropped 19% to $3,913 per tonne on-quarter.

Orocobre said while the global lithium market has suffered a setback due to the coronavirus crisis, the medium- to long-term outlook remains positive, owing to an increase in government regulation and funding.

"The pandemic has delivered accelerated investment by some jurisdictions into electric transportation which should have medium- to long-term benefits but it remains unclear when this will be reflected in lithium chemical prices," the company said in a statement.

The miner also expects to book a non-cash impairment charge of about $28 million before tax in its annual results related to an acquisition and write-downs in finished goods and brine inventory.

(Reporting by Arpit Nayak in Bengaluru, Editing by Sherry Jacob-Phillips)