TOKYO (REUTERS) - Mitsubishi Materials Corp said its subsidiaries falsified data about products, including parts for aircraft and automobiles, for at least a year, the latest in a series of quality assurance scandals involving Japanese manufacturers.

The company said an investigation in the wake of a data-falsification scandal involving joint venture partner Kobe Steel found that Mitsubishi Cable Industries had inappropriately distorted data for rubber sealing products, used in aircraft and cars.

The data was manipulated to match specifications set by the company or its clients and took place in the two-and-a-half years since April 2015, it said in a statement on Thursday (Nov 23).

Another subsidiary, Mitsubishi Shindoh, had manipulated data for metal products, Mitsubishi Materials said. It said it found problems at Mitsubishi Shindoh going back to October 2016.

Mitsubishi Materials said that in both cases, it has not found any safety or legal problems. It did not know whether there would be any impact on its financial outlook, it said.

The company said it has set up a task force to look into the problems and to devise countermeasures to improve quality control.

The news comes after Kobe Steel, Japan's No. 3 steelmaker, admitted in October that workers tampered with product specifications, shaking up global supply chains and forcing global automakers, aircraft manufacturers and other companies to check whether the safety or performance of their products had been compromised.

Mitsubishi Materials has a 45 per cent share in a copper tube joint venture with Kobe Steel, including the Hatano plant that is at the centre of Kobe's data-falsification scandal.

Confidence in Japan's manufacturing prowess has also taken a hit from recent revelations that automakers Nissan and Subaru had failed to comply with final inspection procedures for decades.

Japanese markets are closed on Thursday for a holiday. Mitsubishi Materials shares were little changed on Wednesday.