Director general Digby Jones revealed the outcome of a two-month consultation with business representatives from all the English regions. He has written to the prime minister Tony Blair setting out the concerns.
Mr Jones warned that these assemblies will be 'just another tier of bureaucracy on top of a plethora of decision-making bodies'. He urged ministers at Labour's local government conference in Cardiff this weekend to concentrate on:
* simplifying overly complex regional decision-making processes
* raising the performance of widely-supported regional development agencies
* pushing through proposals for speeding up the planning process
* sorting out problems with the UK's transport infrastructure urgently
* improving the skills base
'This is an ambitious agenda for action that would make a real difference to economic growth in the English regions,' Mr Jones said. 'RDAs are a good route to focus this action. The government must deliver on this agenda and not get distracted by other energy-consuming initiatives that are of questionable value.'
He added: 'Local government can be a solution not a problem. But business does not want an ineffective and expensive talking shop.
'We have little confidence that elected assemblies would be best able to tackle the problems of economic growth and job creation or that they would attract good enough people to make a real difference.
'Having more politicians will not address the need for more investment and skilled people. Another layer of similar politicians will cost money, cause delay and do nothing to help the restructuring of business in England.'
The CBI director general will add that firms are so far unimpressed with the business benefits of devolution.
'Firms in Scotland and Wales accepted, of course, the referendum results creating the Scottish parliament and Welsh assembly. But there is a great deal of scepticism about the positive impact these institutions have had on wealth creation. Political rhetoric does nothing for competitiveness.'
He will conclude: 'Business is not looking for constitutional tinkering. It is looking for action that will make a real difference to the long-standing economic problems that many regions face. RDAs are getting there. Ministers would be wise to ensure they deliver.'
The government plans to publish later this year a white paper on regional governance, which is set to include plans for elected regional assemblies where there is local support.