After weeks of speculation, Brazilian steel group CSN has made an informal $8.1-billion takeover offer for rival Corus Steel.

Corus has been in talks with Tata Steel for a friendly merger ever since the Indian group made a $7.57-billion offer. CSN''s offer is higher than Tata Steel''s bid, which has been accepted by the Corus board, but requires shareholder approval.

CSN said combining the two businesses would make "compelling strategic and industrial logic" and has offered 475 pence per Corus share, compared to Tata''s 455 pence per share proposal.

According to Benjamin Steinbruch, chairman and chief executive, CSN, "A combination of CSN and Corus would create a global powerhouse with market leading positions and exceptional distribution networks across both developed and emerging markets,"

CSN is among one of the largest steel firms with 24,000 employees in Latin America and overseas operations in the US and Portugal.