The Japanese unit of U.S. computer maker Dell Inc. said Thursday it will supply some 56,000 personal computers to the Defense Agency in the largest deal ever for business-use PCs by the subsidiary.

According to the agency, an order for the PCs as well as software and maintenance and other services was put out to open tender on March 27 and was won by Uniadex Ltd., a subsidiary of Nihon Unisys Ltd., for some 4 billion yen.

Dell will supply the PCs to Uniadex, which beat other bidders, including major Japanese PC makers such as NEC Corp., Fujitsu Ltd. and Hitachi Ltd.

The Defense Agency is buying the new PCs to replace personally owned computers that have been used in the workplace. The move will include stepping up internal controls of data management after confidential information was leaked this year from PCs infected with a virus that transmitted information from machines using the Winny peer-to-peer file-sharing software.