WASHINGTON/CHICAGO (REUTERS) - Boeing chief executive Dave Calhoun told reporters on Wednesday the US planemaker expects to resume 737 Max production "months" before its forecasted mid-year return to service.

The company announced a production halt in December, when the global grounding of the fast-selling 737 Max following two deadly crashes in five months looked set to last well into 2020.

The company said on Tuesday it now expects regulators to approve the plane's return to service in the middle of the year.

Calhoun said he did not see recent issues raised about wiring or software as "serious problems."

Boeing shares were down 1.5 per cent on Wednesday (Jan 22).

Calhoun declined to provide a specific date for resumption of production, but said it "will be reinvigorated months before that moment in June because we have to get that line started up again."

The CEO said the company "will slowly, steadily bring our production rate up a few months before that date in the middle of the year."

The latest push back in the forecasted return to service is due to the company's decision to endorse simulator training for pilots before they resume flights, Calhoun said.

"We can get this thing back on its horse and we will," he added.

Calhoun was a director at Boeing for a decade before taking over as CEO earlier this month.

The board ousted Dennis Muilenburg in December amid rising anger by regulators, politicians and customers.