The government has begun making arrangements to set the upper limit for overtime working hours at 720 hours per year, or 60 hours on average per month, as part of measures to correct the problem of long working hours, according to sources.

The envisaged policy initiative also will likely set an upper limit of 100 hours per month even during busy periods for companies.

(Read also: Japan wants its overworked citizens to start weekends early)

Full-fledged discussions on measures to correct long working hours are expected to begin at a meeting of the Council for the Realization of Work Style Reform scheduled for Wednesday. The council is chaired by Prime Minister Shinzo Abe.

For the upper limits under consideration, the government took into account conditions already set for a worker to be recognized as a victim of death from overwork. The conditions stipulate a worker who works 100 hours of overtime in the month prior to showing symptoms of brain or heart diseases or a worker who works more than 80 hours of overtime per month for two to six months prior to showing such symptoms.

While requiring the annual upper limit to be no more than 720 hours, a certain degree of discretion likely will be given to companies by setting the monthly upper limit at 100 hours and the average overtime working hours for two consecutive months at 80 hours per month, the sources said.

(Read also: How Japan's overwork culture leads to 'karoshi')

Jobs related to research and development are likely to be excluded from the upper limit targets. Meanwhile, since transportation, construction and dismantling businesses are currently not covered by the Labor Standards Law, they will likely be subject to the envisaged regulations after a grace period.

The Labor Standards Law stipulates that working hours should, in principle, be no more than eight hours per day and 40 hours per week. However, under Article 36 of the Labor Standards Law, if labor and management sign an agreement, employers can require workers to work overtime or on days off.

Such agreements are commonly called “saburoku kyotei” (36 agreements), after the article that addresses overtime work.

In addition, special provisions established as an exception to the agreement can completely eliminate limits on overtime working hours. Many people have pointed out that saburoku kyotei agreements have been unable to fully function as a brake on long working hours. The government has thus been working to introduce new measures to correct excessive overtime work.