(Adds new walk-off plans by workers, quote, details of workers' complaints, byline and modifies headline)
By Fabian Cambero
SANTIAGO, May 10 (Reuters) - Workers at BHP Billiton's Cerro Colorado copper mine in Chile will strike for 24 hours in the coming weeks to protest recent layoffs and the company's general attitude toward miners, the main union told Reuters on Wednesday.
Earlier on Wednesday, workers briefly blocked the access road to the mine for the same reasons, and later met with the mine's manager.
The recent protests come roughly a month and a half after a fractious 43-day strike at BHP's much larger Escondida copper mine in Chile, and just hours after BHP officially started a sale process for Cerro Colorado, one of its smaller operations in South America.
BHP did not immediately respond to requests for comment.
"We let them know that the mine is going to be shut for 24 hours in a rejection of the company's attitude ... It won't be very far in the future, within the coming weeks," union president Marcelo Franco told Reuters.
"We think there's a clear anti-union message," he added.
Among the workers' various complaints is that BHP is transporting workers to the mine earlier in the morning than previously agreed upon and failing to pay severance to employees.
Cerro Colorado, which together with the Spence mine forms BHP's Pampa Norte division, produced 74,000 tonnes of copper in 2016.
Banking sources have named Chile's Empresas Copec SA and Canadian companies such as Lundin Mining Corp as possible buyers for the deposit. (Reporting by Fabian Cambero; Writing by Gram Slattery; Editing by Jeffrey Benkoe)