Subaru started the year with U.S. inventory of 94,800 vehicles, but stock has since fallen to around 62,000.
"What's more, we will scale back our production a little bit," said Corporate Executive Vice President Toshiaki Okada. "So we think our U.S. supply will come up short. I believe the U.S. business will be impacted."
Subaru is considering how it might smooth supply and distribution, he added.
Globally, Subaru had planned to increase production 0.6 percent to 1.056 million vehicles in the fiscal year ending March 31, 2019. It now plans to cut output 1.3 percent instead.
Okada said the pullback also has complicated Subaru's ramp-up of U.S. output of the Ascent, a new three-row large crossover for which Subaru has high hopes.
"We were unable to boost production while trying to ascertain the quality," Okada said.
As a result of the slowdowns, Subaru lowered its global sales forecast. It originally forecast a 3.1 increase in wholesale deliveries to 1.1 million vehicles. It now says wholesale volume will drop 2.4 percent to 1.04 million vehicles.
Meanwhile, in the U.S., Subaru is being pressured by intensifying competition in its mainstay crossover segment as other brands bring out rival offerings.
Subaru's overall incentives climbed 40 percent through September, from the year before. Its average outlay per vehicle of $1,393 was still well below the industry average of $3,752, according to Autodata Corp. But the brand also resorted to 0 percent financing on such models as the Outback crossover — Subaru's best-seller in the U.S. — which is getting long in the tooth.
Longer term, Subaru executives believe the quality troubles are just a bump in the road. There is still robust demand for Subaru products, they say. And once the quality concerns are under control and supply has been ramped up, dealers should be able to tap that demand.
"Actual sales in the U.S. are very good," Okada said. "So, I believe we have potential."
Jack Walsworth contributed to this report.