Adds details on operations, context in paragraphs 6-11

By Tibisay Romero

MORON, Venezuela, June 25 (Reuters) - Venezuela's Moron Petrochemical Complex, the country's second largest in operation, was restarting on Thursday after a preventive shutdown due to quakes that caused infrastructure damage, the local chief of firefighters said.

The quakes, which killed more than 160 people, left Venezuela's vast oil and gas infrastructure mostly untouched, including the 146,000-barrel-per-day El Palito refinery in central Carabobo state near the epicenter, according to preliminary reports from workers. But assessments are expected to continue this week as repairs are done, they added.

Carlos Miquileno, head of firefighters for Moron and Urama, also said that a key state-operated power plant in the central region, Planta Centro, was expected to restore supply starting on Thursday.

Workers from the Moron complex had been told not to come in while an initial assessment on damages was conducted, sources from that center had said earlier, adding that a leak from a storage tank had been detected on Wednesday.

It was not immediately clear if the leak was repaired. State petrochemical company Pequiven and state energy company PDVSA have not provided information about the status of their operations. Venezuela's oil ministry did not immediately reply to a request for comment.

In Moron, one of the most affected cities, authorities are updating the death toll and sending injured people to hospitals, nurses and doctors said.

As widespread power outages hit many regions in the country, oil executives from foreign firms operating with state-run PDVSA in joint ventures have noted that crude output levels could be hit by the lack of electricity in some oilfields.

Venezuela was producing some 1.2 million barrels per day (bpd) of crude before the quakes.

Many energy companies with operations or offices in the country have been accounting for staff as they conduct initial assessments on the condition of oilfields, plants and refineries, but almost none of the cities with official reports of severe damages include critical oil infrastructure.

U.S.' Chevron CVX.N, Italy's Eni ENI.MI, Spain's Repsol REP.MC and UK's Shell SHEL.L said all personnel had been accounted for.

Chevron said the company "remains operational," while Eni and Repsol said the quake had not impacted their operations. The Perla project by Eni and Repsol, which is responsible for 50% of the gas feed demanded by the country's thermoelectrical plants, was not affected and gas output there remains uninterrupted, a Repsol spokesperson said.