Toshiba Corp. on Saturday reported a group operating loss of just under ¥90.5 billion ($734 million) for the first half of fiscal 2015, as its home appliance and other mainstay businesses struggled amid an accounting scandal.

It is the first time in six years that Toshiba has marked an operating loss for the April-September period. Toshiba said it sued its former management — three former presidents and two chief financial officers — over the improper accounting practices spanning roughly seven years, and is seeking a total of ¥300 million in damages. Those being sued include Hisao Tanaka, Norio Sasaki and Atsutoshi Nishida, who stepped down in July to take responsibility for improper accounting. Toshiba also said it will reprimand 26 executives over the accounting scandal Monday.

For the year through March 31, Toshiba did not announce earnings forecasts as it is still trying to lay out restructuring plans to emerge from the crisis.