Hitachi Ltd. (6501.TO) said Tuesday its joint venture with LG Electronics Inc. (066570.SE) is being investigated by the U.S. Department of Justice for alleged antitrust violation.

A Hitachi spokeswoman said the joint venture, Hitachi-LG Data Storage Inc., will fully cooperate with the U.S. authorities, but she declined to elaborate on the investigation.

-By Kazuhiro Shimamura, Dow Jones Newswires; 813-6895-7566; kazuhiro.shimamura@dowjones.com