The Fair Trade Commission ordered Japan Airlines on Friday to discontinue advertisements and announcements of discount fares on domestic routes the carrier has never offered.
A Japan Airlines official said the carrier has stopped the ads following a notice from the government's competition policy watchdog.
The commission issued a cease-and-desist order to Japan Airlines Domestic, which operates the group's domestic flights, concerning ads that appeared in newspapers and flyers as well as fare announcements in JAL timetables.
This represents the first such order the commission has issued over public transportation fares.
The commission alleged JAL violated provisions of the Act Against Unjustifiable Premiums and Misleading Representations.
In the one-year period through January, JAL published discount fares on five routes, including Okayama-Tokyo and Hiroshima-Tokyo.
According to the commission, the discount fares were set on limited domestic flights out of Tokyo, Osaka and Kobe to regional cities. But JAL said in its ads and announcements that flights from the regional cities bound for the three major cities were also available at the lowest fares.