JAKARTA, Indonesia — Indonesia’s national airline has told Boeing that it wants to cancel an order of 737 Max 8 jets, the carrier’s spokesman said on Friday, the first publicly confirmed attempt to cancel a deal for the planes since they were grounded around the world this month after two deadly crashes.

The airline, Garuda Indonesia, said that its passengers had lost confidence in the model after the crashes. It said that it sent a letter to Boeing on March 14 seeking to cancel its order of 49 more planes; it had ordered 50, just one of which has been delivered. The deal is estimated to be worth $4.9 billion.

“Continuing the Max order does not benefit Garuda,” said the spokesman, Ikhsan Rosan. “Our passengers, psychologically, they don’t trust flying with Max anymore. They often asked during booking what type of aircraft they would be flying on.”

A Boeing spokesman declined to comment. More than 4,000 737 Max planes, Boeing’s best-selling aircraft, are on order by airlines around the world. Boeing’s stock, which has dropped about 12 percent since the March 10 Ethiopian Airlines crash in which 157 people died, fell nearly 3 percent on Friday.