TOKYO (BLOOMBERG) - Japanese advertising giant Dentsu Inc is considering dropping a principle set by a former president encouraging staff to stick to a goal even to the point of death after a 24-year-old employee committed suicide because of overwork.

The principle in question was one of 10 written by Dentsu's fourth president in 1951 and they were looked on by employees as the pinnacle of commitment, Mr Shusaku Kannan, spokesman at Dentsu, said by e-mail.

The bereaved family of the female employee who killed herself on Christmas Day in 2015 is opposed to the principles, saying they symbolise Dentsu's culture of excessively long hours, the Asahi newspaper reported.

The employee repeatedly worked long hours and clocked up 105 hours of overtime over the course of a month from October 9, 2015, according to an earlier report by the newspaper.

The principle under scrutiny, as translated by Asahi, reads: "If you have tackled it, don't relinquish it. Even if you are killed, don't relinquish it until you achieve your goal."

Dentsu's Mr Kannan said the principles were those of the former president and not an official company mantra. New pocketbooks containing the principles are scheduled for distribution by the firm in December, the Asahi said.

The company said earlier this month that it is cooperating with a labour ministry investigation of its labour practices.

From November, workers have been barred from logging more than 65 hours of overtime a month, down from the previous limit of 70.