(Recasts with comment from Ternium)
SAO PAULO, Dec 2 (Reuters) - Two controlling shareholders of Brazilian steelmaker Usinas Siderúrgicas de Minas Gerais SA exchanged on Tuesday accusations over the dismissal of senior executives and a proposed investigation by regulators.
Nippon Steel & Sumitomo Metal Corp asked securities regulator CVM to investigate efforts by Italo-Argentine industrial conglomerate Techint Group and its subsidiary Ternium SA to reinstate three executives fired by the board of the Brazilian mill known as Usiminas, according to a securities filing.
Ternium shot back with a public statement refuting Nippon's accusations, calling its conduct "illegal and irresponsible" and questioning the Japanese shareholder's relationship with members of the steelmaker's board.
Nippon had raised the prospect of a negotiated end to the dispute between partners of Usiminas, Brazil's largest listed flat steelmaker. (Reporting by Guillermo Parra-Bernal and Brad Haynes; Editing by Chizu Nomiyama and Alan Crosby)