Mitsubishi Motors Corp’s top two executives are likely to resign over the Japanese automaker’s manipulation of fuel economy data, Japanese media reported on Wednesday, in a scandal that has halved the company’s market value in a week.

Chairman and Chief Executive Officer Osamu Masuko has already told some affiliated dealers and parts makers of his intention to resign, the Yomiuri daily said. Separately, the Mainichi daily reported President and Chief Operating Officer Tetsuro Aikawa has decided to step down.

Japan’s sixth-biggest automaker said recently it used fuel economy testing methods that did not comply with Japanese regulations for 25 years. It said it would set up an external committee to investigate the matter and report the results in three months.

Meanwhile, Mitsubishi Motors Corp said Japanese orders for its cars have halved since it revealed last week it cheated on fuel economy tests, intensifying concerns over its prospects given an already chequered history of scandals.

The automaker said it may approach its financial backers, which include other Mitsubishi Group companies, for assistance if necessary, but its financial position is strong and it sees no need for fresh funding for now.