Slaughter and May has reasserted its position as lead adviser to the Corus Group, formerly British Steel, by advising on its proposed £3bn merger with Brazilian steel producer Companhia Siderugica Nacional (CSN).

The strength of Slaughters' relationship with Corus was questioned in April when the steel giant turned to Lovells to advise it on the £900m disposal of its aluminium business.

However, this latest deal brings confirmation that Corus remains close to Slaughters, which advised on the privatisation of British Steel back in 1988 that created the company.

Slaughters corporate partner Andy Ryde, the firm's main client contact, is leading the team advising Corus.

"The firm would expect to get instructed for large international deals by the company," Ryde said. "It is the slowest M&A market for 10 years or more and it is a lot quieter at the moment than it has traditionally been at the firm, so it is nice to get this deal."

Clifford Chance is advising long-term client CSN, led by New York-based corporate partner Anthony Oldfield.

"The New York office has advised CSN for many years, but it is too early to say who will advise the new merged company," Oldfield said.

The deal, which was announced last week, will create a company with a market capital of more than £3bn and sees two significant players in the industry join forces. Corus is one of Europe's market leaders in carbon steel, which will come together with CSN, one of the world's lowest cost steel producers.

The merger is still subject to regulatory clearance from numerous bodies in both countries and is expected to be closed in the first quarter of next year.

The instruction will give Slaughters' M&A ranking for the second half of 2002 a welcome kick-start. The firm came only 14th in Mergermarket's European table for the first half of the year.