United Airlines Holdings Inc. has decided to give up on flying the Boeing Co. 737 Max until June, two months longer than rival U.S. carriers, as the regulatory fate of the grounded aircraft remains unclear.

The Max will be removed from its schedule until June 4, the Chicago-based carrier said Friday. American Airlines Group Inc. and Southwest Airlines Co., the other U.S. Max operators, recently removed the plane from service until April.

“By moving the return to service date back more than just a month — as we have done previously throughout 2019 — it allows us to have more certainty by providing our customers and our operation a firmer and more definitive timeline,” United said in a statement. The move also helps the airline plan better for 2020.

Regulators worldwide grounded the top-selling Boeing model in March after two crashes killed 346 people. Boeing has been forced to abandon its goal of securing approval this year for software changes meant to reduce the effects of a flight-control system on the Max.

United expects the Max grounding to affect more than 11,500 flights for 2020, including about 108 a day in May and the affected portion of June. The carrier had expected to receive additional planes this year and next, which leads to an increasing schedule impact.