Four of All Nippon Airways' (ANA) domestic pilot unions are threatening to go on strike.

The Air Nippon Crew's Association, Air Nippon Network Pilot Union, the Air Next Crew's Association and the Air Central Pilots' Union are threatening to go on a 24hr strike as of midnight today, says ANA.

These unions are threatening to strike in an effort "to express dissatisfaction with the management's stance in their year-end round of talks," it says.

If the strike goes "ahead 171 domestic flights will be cancelled or delayed" but no international flights will be affected, it adds.

An ANA spokeswoman says the unions are unhappy that ANA group is unwilling to attend the talks.

She says the ANA group stance is that the pilot unions should negotiate with the management of the respective subsidiaries.

One reason the pilots want ANA group to be involved in the talks is because the pilots want to see how they can transition from small aircraft to larger aircraft.

Japanese pilots' unions typically give notice of strike action several times per year as they negotiate bonuses, wages and other issues with management.

But the four unions here have followed through with their threat before. In April this year, these four went on strike, forcing the airline to cancel over 100 domestic flights.

That strike was over similar issues, adds the ANA spokeswoman.

Source: Air Transport Intelligence news