TOKYO, June 7 (Xinhua) -- Japan's Ube Industries Ltd. said Thursday that an internal probe at the firm had revealed that substandard quality checks may have been carried out for decades by the chemical product maker.

A probe launched in February and carried out partly by external lawyers concluded in part that the company "had not prioritized ensuring quality as much as manufacturing."

Substandard quality inspections, the probe revealed, affected 24 products that have been shipped to 113 companies. The improper inspections spanned all of Ube Industries' six group companies.

According to Ube Industries, to take responsibility for the scandal, President Yuzuru Yamamoto will return his salary for June, while pay cuts will be dished out to five other senior members of the firm including Chairman Michio Takeshita.

The punishments for the board members and other executives included pay cuts of between 30 to 60 percent, the firm said.

The embattled chemical product maker had initially said that the substandard checks involved a plant in Chiba Prefecture, close to Tokyo, and some polythene products. One such case involved the falsification of the origin of raw concrete the company was using.

The probe also found that such substandard quality checks and improprieties had been routinely carried out by Ube Industries, with such practices endemic in the group's working culture for a long period of time dating back to the 1970s.

Investigators said the chemical maker had prioritized fulfilling delivery deadlines, rather than focusing on the quality of its work. A lack of personnel also compounded the problem.

Ube Industries is the latest Japanese manufacturer to join a long list of multinational corporations in Japan who have been found to have rigged data or used uncertified staff to carry out inspections.

These included Kobe Steel Ltd., Nissan Motor Co., Subaru Corp., with the growing list continuing to dent global faith in Japan's once highly regarded manufacturing sector.