Boeing slips as it considers slashing production for the problematic 737 Max

• Boeing is mulling cutting or halting production of the grounded 737 Max, The Wall Street Journal reported Sunday.
• Shares of the company fell as much as 4.2% in early trading Monday.
• The plane has been grounded since March following two fatal crashes. Although Boeing was optimistic it would return to service in 2019, that timeline has been pushed back and the plane will remain grounded until 2020.
• Watch Boeing shares trade live on Markets Insider.

Boeing stock is falling as the company mulls whether or not it should slow production of the 737 Max or stop making the planes altogether as the timeline for its return to service gets pushed into 2020.

Shares of the aerospace company fell as much as 4.2% in early trading Monday after The Wall Street Journal reported Sunday that Boeing discussed the future of the grounded 737 Max at a board meeting and could come to a decision about production as soon as Monday.

"We continue to work closely with the FAA and global regulators towards certification and the safe return to service of the MAX," Boeing told Markets Insider in a statement. "We will continue to assess production decisions based on the timing and conditions of return to service, which will be based on regulatory approvals and may vary by jurisdiction."

Boeing had already stepped down production of the plane following its grounding in March after crashes in Indonesia and Ethiopia killed 346 people. In April, the company said it would make 42 of the 737 Max airplanes per month instead of 52.

On the company's second-quarter earnings call in July, Boeing CEO Dennis Muilenburg said that the company might need to asses "possible further rate reductions or other options, including a temporary shutdown of the MAX production," should the anticipated return to service timeline change.

Earlier in the year, Boeing was optimistic that the plane could return to service by the end of 2019. But in December, the FAA called the timeline "not realistic" and confirmed that the plane will remain grounded this year.

It's now unclear when the beleaguered airplane will return to service. Airlines such as United and Southwest that fly the 737 Max have said that they will not schedule any flights with the aircraft until March 2020. American Airlines announced on Thursday that it has canceled all flights with the plane until April 7, 2020.

Boeing is up roughly 6% year-to-date through Friday's close.