Nippon Steel Corp. and Brazil's Gerdau SA are in talks to stave off a rival $2.9 billion bid for a stake in Usinas Siderurgicas de Minas Gerais SA, or Usiminas, said two sources familiar with the negotiations.

Nippon Steel, Japan's largest steelmaker, may exercise its right of first refusal and buy out its partners in the group that controls Usiminas to thwart the takeover offer from Cia. Siderurgica Nacional SA, or CSN, said the sources, who asked not to be named because the talks are private.

Nippon Steel would then resell to Gerdau part of the 26 percent stake in Usiminas held by partners Camargo Correa SA and Grupo Votorantim, they said.