OSAKA -- The labor ministry on Thursday expanded its investigation into consumer finance company Takefuji Corp. on suspicion it forced staff to work overtime and failed to pay wage premiums, according to ministry officials.

Leading the investigation, the Osaka Labor Bureau said employees in Osaka of the Tokyo-based company averaged around 100 hours of monthly overtime beyond an agreement between labor and management.

The Osaka bureau has been investigating overtime at Takefuji's Osaka units since July 2001, after being contacted by former employees. It decided to expand the investigation to cover the Tokyo head office and several other offices because it suspects an order was issued in other parts of the country as well, the officials said.