Mitsubishi Motors Corp. fell the most in more than a decade in Tokyo trading after the company said it will hold a briefing about its improper handling of fuel economy tests.
The shares plunged 15 percent, their biggest drop since July 2004, after Mitsubishi Motors issued a statement saying President Tetsuro Aikawa will brief reporters Wednesday. The automaker improperly handled fuel economy data involving its minicars in Japan, Yoshifumi Nagai, an official with the nation’s transport ministry, said by phone.

Mitsubishi Motors joins Hyundai Motor Co., Kia Motors Corp. and Ford Motor Co. in recent cases of automakers mishandling their fuel economy testing or reporting. Hyundai and Kia agreed to pay fines and forfeit emissions credits in late 2014 to settle U.S. claims they overstated mileage ratings. Ford lowered ratings for hybrid models in both 2013 and 2014. The auto industry is facing more intense regulatory scrutiny after Volkswagen AG’s admission last year that it had cheated U.S. emissions tests.