Slowing growth in the maturing U.S. shale industry and spending cuts by oil and gas customers will lead to a consolidation of oilfield service suppliers, Halliburton CEO Jeff Miller told investors on Sept. 4.

The largest U.S. supplier of fracking services to oil and gas producers expects its third-quarter results will be at the low end of its earlier forecasts as activity slows.

The company also plans to reduce its 2020 capital spending, Miller said at the Barclays CEO Energy-Power Conference in New York.

North American spending growth on oil and gas production will slow to a 2% this year, according to a Barclays survey released this week, down from a January estimate of a 9% gain. Analysts for the bank expect spending in the second half of the year to be 15% below the first half.

Independent pressure pumper Liberty Oilfield Services also pointed to slowing hydraulic fracturing activity during a presentation at the Barclay's conference.

“I think the fall off may be quicker and harder and earlier than a number of people expected,” Michael Stock, Liberty’s finance chief, told attendees.

Pressure pumping forces water, sand and chemicals underground to release oil and gas trapped in shale rocks, and to apply cement to complete a well.

Halliburton’s Miller said some E&P companies have continued to attempt to push down service pricing, particularly where productivity gains have slowed or efficiencies are harder to achieve.

Oilfield service companies’ margins on fracking have been squeezed due to an oversupply of equipment and as customers have tightened spending to focus on shareholder returns.

U.S. energy firms have cut the number of oil drilling rigs for the nine straight months to its lowest since January 2018, according to oilfield service company Baker Hughes.

Miller said he anticipates more consolidation among U.S. pressure-pumping providers, but he does not expect Halliburton to be active in those mergers and acquisitions.

“Building is cheaper for us,” he said.

Although North American oilfield activity has slowed, the company expects continued growth in other regions.

“International spending has returned and, in my opinion, will continue to grow,” Miller said.

Halliburton shares were up 7 cents, or 0.4%, at $18.83 in morning trading. They are off about 29% in the year to date.