The Tokyo District Public Prosecutor's Office is mulling charging an employee of Nihon Keizai Shimbun Inc. with insider trading, sources said.
The male employee of the advertising department at the company's head office in Tokyo is suspected of having obtained advance information of a legal notice for publication in the Nikkei business newspaper, and pocketing several dozen million yen in profit by using that information.
The newspaper publisher conducted an internal investigation after the government's Securities Exchange and Surveillance Commission probed the case in February by visiting the company's office and questioning the employee.
The man has admitted to insider trading, according to the company.
The prosecutors are said to be investigating the case together with the commission.
The employee, in his 30s, had access to information that included financial results and upcoming stock splits, the sources said Sunday.
Through short-term transactions, the man is suspected of earning profits by trading in stocks of more than 10 companies, the sources said.
On Feb. 24, Takashi Kageyama, managing director in charge of advertising at Nihon Keizai, resigned and the head of the ad bureau was removed from his post, while remuneration was suspended for three months for top executives.
To prevent similar misdeeds, the company requested that employees in news editing, advertising and marketing refrain completely from trading in stocks. They had already been banned from conducting short-term trading.