UPDATE 4-Magnitude 6.8 earthquake rocks northern Chile; minor damage, no casualties

(Updates with detail on damages, no casualties)

June 3 (Reuters) - A magnitude 6.8 earthquake struck Chile´s mineral-rich northern desert early on Wednesday, monitoring groups confirmed, though damage was minimal and mining companies told Reuters their operations had not been affected.

In Chile, a South American nation often rocked by tremors, mine facilities and other infrastructure are built to withstand extraordinarily large quakes.

Wednesday´s tremor struck at a depth of 145 km (90 miles), the German Research Center for Geosciences said, and its epicenter was about 62 km southwest of San Pedro de Atacama, close to several large lithium and copper mines, including Codelco’s sprawling Chuquicamata and Ministro Hales deposits.

Codelco, the world’s largest copper producer, and top mining companies BHP and Antofagasta told Reuters the quake caused no damage or operational problems at their sites.

The world’s top two lithium miners, Albemarle Corp and SQM, also confirmed operations were normal despite the proximity of the tremor to their mines in the Atacama salt flat.

Antofagasta´s regional government reported minor landslides on local roads and scattered power outages but no casualties. (Reporting by Subrat Patnaik in Bengaluru and Fabian Cambero in Santiago; additional reporting by Dave Sherwood, Editing by Lisa Shumaker and Steve Orlofsky)