A 24-hour pilots' strike at All Nippon Airways forced Japan's second-largest carrier on Wednesday to scrap or delay nearly 170 domestic flights, company officials said.
No international flights are affected by the dispute, ANA said.
A spokesman for the carrier said it had cancelled 137 domestic flights and delayed 30 -- more than 18 percent of its scheduled services -- and that some 9,400 passengers were being affected.
The pilots' unions of four ANA subsidiary airlines launched the strike "to express dissatisfaction with the management stance in their spring round of talks", the airline said in a statement.
Rival Japan Airlines was able to avert a similar strike at the last minute in negotiations with its union.
The strike was due to end at midnight on Wednesday (1500 GMT).
"There is no serious confusion in the airports as we had informed our passengers in advance about the strike," the spokesman said.
"For some passengers who arrived at airports not knowing about the strike, we are showing them alternative transport means such as railways. The operations will return to normal from Thursday."