The admissions by Associated Lead Mills Ltd and H.J Enthoven Ltd (trading as BLM British Lead) follow a Competition and Markets Authority (CMA) investigation.

A third company, Calder Industrial Materials Ltd, is also under investigation in relation to one of the arrangements and has not made any admissions.

The trio together account for about 90% of UK rolled lead supplies.

The CMA said that Associated Lead Mills and BLM British Lead entered into arrangements including:

• sharing the market, including by arranging not to target certain customers
• colluding on prices
• exchanging commercially sensitive information on prices
• arranging not to supply a new business that risked disrupting the firms’ existing customer relationships and was also a potential competitor in the market.

Associated Lead Mills and BLM British Lead have now admitted to their parts in these arrangements, which took place between October 2015 and March 2017.

The two firms have agreed to pay maximum fines totalling more than £11m with the exact figure to be determined at the end of the CMA’s investigation if there is a formal final decision that the law has been broken.

Calder Industrial Materials has made no admission of liability and the CMA’s investigation is continuing. No assumption should be made that Calder Industrial Materials has broken the law.