A Boeing 737 MAX 10 fuselage is pictured during the opening ceremony for the company's new North Line assembly line, which will produce 737 MAX aircraft, at the Boeing Everett Factory in Everett, Washington, on July 10, 2026.

Boeing 's 737 Max production is taking "a little bit longer" than expected to stabilize, and the company expects to increase its output of the planes next year, CEO Kelly Ortberg told investors Wednesday.

Boeing stock extended its losses for the day and was down more than 5% in afternoon trading after Ortberg's comments.

The manufacturer has been working to steadily ramp up the output of its best-selling plane after years of safety and quality crises. Ortberg said wing production at its Renton, Washington, factory is a constraint now, adding the company has plans in place to address it.

Boeing is producing about 47 of the aircraft per month.

Ortberg reiterated to investors at a Morgan Stanley industry conference that he expects certification of the Max 10, the largest model in the family "very soon." That plane is years behind schedule.

Kelly didn't say that he expected aircraft orders from China when President Donald Trump is scheduled to host Chinese leader Xi Jinping at the White House on Sept. 24.

Orders from China are "going to be announced by the airlines at their pace," he said.