Dentsu Inc. said Friday it will delete from its employee handbook its 10 principles encouraging hard work amid heightened criticism over the suicide of a young employee.

The principles, written in 1951 by former President Hideo Yoshida, include one that says, "Never give up on your task. Do not let go even if you are killed."

Yoshida was an influential figure in the advertising agency and helped to rebuild the company after World War II.

Dentsu also said it will employ a new performance appraisal scheme for workers in managerial posts to reflect evaluation from subordinates starting next month.

As part of efforts to improve the work-life balance of employees, it aims to have them take at least 50 percent of annual paid holidays, the company said.

According to the latest available data from the labor ministry released in 2015, workers at Japanese private firms took just 48 percent of their annual paid holidays on average.

Dentsu also plans to consult its business partners when formulating new rules so as to prevent its employees from working long hours.

Labor authorities started investigating the advertising giant over suspected illegal overtime work by its employees after a 24-year-old female employee committed suicide in December last year. Her death was later deemed to be karoshi, the Japanese word for death by overwork.