CHICAGO — Boeing will cut production of its large 787 aircraft after a structural flaw was discovered in some undelivered planes.

The production rate for the 787, which it calls the Dreamliner, will fall below five per month and the Chicago company said today that it now anticipates that it will deliver less than half of the 787s remaining in its inventory this year.

“We will continue to take the necessary time to ensure Boeing airplanes meet the highest quality prior to delivery,” the company said in a prepared statement. “Across the enterprise, our teams remain focused on safety and integrity as we drive stability, first-time quality and productivity in our operations.”

Shares are down more than 2% before the opening bell.

Boeing delivered 12 of the 787s in the second quarter. It has delivered 14 for the year to date.

In May members of Congress sought records from Boeing and the Federal Aviation Authority about production problems on the 787 and the 737 Max.