All Nippon Airways in Japan is to cancel all Boeing 787 flights until at least the end of May.
International regulators grounded all 787 Dreamliners in January for safety checks on their lithium ion batteries.
ANA is cancelling more than 1700 flights in April and May, a period that includes Japan's Golden Week holiday.
It takes the total number of affected ANA Dreamliner flights to 3600.
ANA is Boeing's biggest Dreamliner customer.