Mandiant, Board Sued Over $1.2 Billion FireEye Take-Private Deal

A Mandiant Inc. investor sued in Delaware to challenge its $1.2 billion take-private sale of the FireEye Inc. cybersecurity business to Symphony Technology Group, claiming the deal violated a law requiring shareholder approval when a company sells “substantially all” of its assets and goodwill.

The lawsuit, made public late Monday in Delaware Chancery Court, targets Mandiant, its founder Kevin Mandia—who led the combined company before the FireEye spinoff closed in October—and other members of its board. The suit doesn’t name STG, a private equity firm, as a defendant.

It accuses Mandia and the board of forcing the deal through without ...