The closure of the plant, which primarily produces highwall miners, will impact about 40 workers.

In a statement Cat said it would offer transitional support as well as severance packages to all.

Production will be moved to the OEM’s facility in Houston, Pennsylvania, about 30 minutes from Pittsburgh.

“We value our employees' contributions and these actions are not a reflection of them but rather the result of a need to make our underground mining business more efficient and competitive,” spokeswoman Barbara Cox said, adding that the move was made to “best position the company for long-term success”

It is the second such consolidation for Illinois-based Caterpillar in 2013, as it announced plans earlier this year to move its Tazewell, Virginia operations to the Houston plant.

The move comes just a week after the company confirmed the closure of its Kilgore, Texas assembly facility, which it said was in response to lacking demand for mining machinery.

The facility’s production will soon move to Kansas and Wisconsin.

The Kilgore location was formerly owned by Bucyrus, which Cat purchased in 2011.

Cat also announced idles of smaller plants this year including Summerville, South Carolina; Owatonna, Minnesota; Toronto and Sudbury, Canada.

The global mining industry slump was cited as the impetus for all of the closures.

In all, an estimated 13,000 employees have been cut from the OEM’s payroll in the past year.

In its earnings report last month, Cat said third quarter mining equipment sales were about $US3 billion, a 42% year-on-year drop.