U.S. shale fracking services provider Liberty Oilfield Services activated its 24th hydraulic fleet in January and plans to build an additional fleet, the company said on Feb. 6.

The move comes as many companies that provide hydraulic fracturing services are idling equipment amid oversupply and weak pricing. Hydraulic fracking pumps water, sand and chemicals at high pressures to release trapped oil and gas.

Top oilfield provider Schlumberger last month said it was reducing the number of its active fleets by 50%. Others have been idling equipment as investors pressure oil producers to focus on returns rather than costly growth projects.

Denver, Colorado-based Liberty Oilfield Services said its 25th fleet would be built for an existing customer.

“It takes special circumstances in today’s market to build capacity, but this was just such a case,” CEO Chris Wright told investors.

Liberty shares were down about 4% at $8.48 in late-morning trading.

Rival Patterson-UTI Energy Inc., which also held an earnings conference call on Feb. 6, said it was working to “reposition” two hydraulic fracturing fleets after a major customer stopped drilling in a U.S. shale basin. It did not name the customer or basin.

Shares of Patterson, which also owns and operates drilling rigs, fell 9.7% to $7.61.