Boeing : may cut or halt 737 output if return to service delayed - CEO

(Reuters) - Boeing does not rule out further reducing or temporarily shutting down production of its grounded 737 MAX aircraft if its estimates on the timing of a return to service have to be revised, Chief Executive Dennis Muilenburg said on Wednesday.

Boeing cut production of its best-selling jet by 20 percent in April to 42 a month from 52 a month, weeks after it was grounded worldwide in the wake of two fatal crashes.

Boeing estimates the return to service will begin "early in the fourth quarter" and based on this forecast it plans to maintain production at 42 a month, rising to the original goal of 57 a month in 2020, Muilenburg told analysts.

He said Boeing would continue assess these plans, however, and added: "Should our estimate of the anticipated return to service change, we might need to consider possible further rate reductions or other options including a temporary shutdown of the MAX production."

(Reporting by Tim Hepher; Editing by Mark Potter)