Benesse Holdings Inc. said Friday it posted its first group net loss since going public in 1995 as it incurred special losses to deal with the aftermath of the nation's biggest corporate data theft by a former employee.

The Japanese provider of education services logged a consolidated net loss of ¥10.71 billion ($89.4 million) for business 2014 ended March 31, after logging a profit of ¥19.93 billion the previous year.

The company booked an extraordinary loss of ¥26 billion that includes expenses for mailing apologies to customers and for strengthening its data management capabilities after personal data on around 40 million customers was taken by a contract employee last year to sell to name-list providers.

Benesse said group operating profit plunged 18.4 percent from a year earlier to ¥29.23 billion for fiscal 2014, while sales fell 0.7 percent to ¥463.26 billion, dropping for the first time in five years.

Growth in the domestic nursing care business and the education business in China failed to offset its sluggish correspondence education business at home.

"We booked all costs to deal with the (data leakage) incident in fiscal 2014," Benesse Holdings Chairman and Chief Executive Officer Eiko Harada said at a news conference. "We believe we have restored trust gradually."

While noting its corporate performance ahead will hinge on whether its education business can recover in Japan, Harada pledged that Benesse will boost investment, carry out structural reforms and accelerate businesses abroad.

For the business year through next March, the company is expecting a group net profit of ¥3.80 billion, but expects operating profit to plunge 53.8 percent to ¥13.50 billion, on sales of ¥459.20 billion, down 0.9 percent.