Usiminas, the Brazilian steelmaker embroiled in a board fight between Nippon Steel & Sumitomo Metal Corp. and the Techint Group, said the regulator ordered the two to make an offer for all its voting stock, adding a new twist in the battle for control. Nippon Steel and Techint are the largest members of the group that controls the Belo Horizonte-based company formally known as Usinas Siderurgicas de Minas Gerais SA.