CME, the world's largest futures exchange, is responding to a "key need to execute with confidence and clear with confidence," in developing the new contract, said Harriet Hunnable, the exchange’s managing director of metals.

The LME's offering is currently the benchmark for the $90 billion aluminium market, but the exchange has been beset by criticism over long delays faced for delivery of metal from its warehouses and a lack of transparency in its price-setting mechanism.

There was a guarded welcome for the CME's proposal, although some said that until further details emerge they would reserve judgement on the potential impact of the move.

CME’s contract will be physically deliverable and is thought to be similar to the LME product, except CME’s contract will be monthly whereas LME’s is daily.