Brazilian steelmaker CSN has asked the nation's antitrust watchdog for permission to appoint members to the board of rival Usinas Siderurgicas de Minas Gerais SA, in which it owns a significant stake, because it is dissatisfied with some directors, Valor Economico newspaper said on Wednesday. Cia Siderurgica Nacional SA, as the company is formally known, says the two board members representing minority shareholders in Usiminas have failed to meet their fiduciary duty, Valor reported, citing CSN Vice President Paulo Caffarelli.