Guy Dollé, chief executive of European steel group Arcelor, last night launched an angry attack on Lakshmi Mittal, saying that the Indian billionaire had behaved improperly in initiating a €18.6 billion takeover bid for the group and presided over a company with poor standards of corporate governance.

Mr Dollé said the Arcelor board had decided Friday's offer by Mittal Steel to take control of the Luxembourg-based steelmaker - and create a huge steel company with output three times higher than its closest rival - was "150 per cent" hostile. Arcelor has formally rejected the bid.

Mr Dollé said Mr Mittal, chairman and main owner of the Netherlands-based Mittal, had broken "the unwritten rules" by raising the matter briefly with him at a dinner in London on January 13th but without any detailed documents or figures.

Mr Dollé said he would be starting talks with shareholders to try to convince them the existing Arcelor management was capable of doing a better job in running the company than Mittal's executives.