(Adds details on CSN)
By Alberto Alerigi
SAO PAULO, April 28 (Reuters) - Brazilian steelmaker Usiminas appointed Elias Brito as chairman on Thursday in a rare unified vote between two controlling shareholders that have been battling for control of the company for 18 months.
Brito will replace Marcelo Gasparino, who had been appointed last year by minority shareholders after the controllers, Japan's Nippon Steel & Sumitomo Metal Corp and Italo-Argentinian Techint, could not agree on a candidate.
Sources close to Usiminas management said the consensus between the warring factions had been formed in order to block advances by rival steelmaker CSN which received permission this week from Brazil's anti-trust body Cade to nominate two members to the board.
Nippon, Usiminas and Techint filed three different injunctions trying to block CSN's participation in the board member vote but all were rejected by judges in Belo Horizonte and Brasilia.
Cia Siderurgica Nacional SA, as CSN is formally known, is a shareholder in Usiminas but had been prohibited from electing board members due to anti-trust concerns. São Paulo-based CSN owns 14.1 percent of voting shares and 20.7 percent of non-voting stock of Usiminas. The value of CSN's original 3 billion real investment in Usiminas in 2011 has declined 85 percent.
"It's the Steinbruch effect," one source said, referring to Benjamin Steinbruch, the Chief Executive of CSN.
CSN has long been rumored to want a bigger role in running Usiminas, with which it competes in the Brazilian flat steel market. The company had previously been told by Cade to sell down its stake, but has delayed doing so.
CSN and Techint declined to comment about the new chairman. Nippon Steel did not immediately respond to a request for comment.
"It's the first sign that a shred of rationality has returned ... Since September 2014 there has been no consensus," said a second source close to the controlling shareholders.
Shareholders at the assembly also raised the number of board seats to 11 from 10, and elected three independent members that were endorsed by minority shareholders CSN and Grupo BTG Pactual SA. (Reporting by Alberto Alerigi; Writing by Tatiana Bautzer and Stephen Eisenhammer; Editing by James Dalgleish)