In an annual survey of businesses employing 2.4 million people, the CBI also found widespread anxiety about the impact of a whole range of new employment regulations, including restrictions on working-time.
Meanwhile, the Engineering Employers' Federation accused the Government of encouraging industrial action by insisting that ballot papers should include the information that strikers will not be dismissed for the first eight weeks of action.
David Yeandle, of the federation, said that if the amendment to the Employment Relations Bill was carried it would increase the likelihood of a yes vote.
In the CBI study, which covered 830 firms, more than one in four said that the effect of fresh labour law would be negative, but among those with more than 5,000 workers the proportion was two out of five.
John Cridland, CBI human resources director, said the new flexible labour market in Britain could be hampered by new legislation. "The Government should not assume that larger firms can shrug off the burden of compliance, nor that they are less likely to be affected by Government regulation," he said.
In what seemed to signify a hardening of the CBI line on new employment law, its second annual employment trends survey said: "More legislation can only distract employers' attention from the real business of improving the management and development of people."
The survey found that around half the firms employing more than 500 assumed they would be faced with a union recognition claim . Nearly a third of the privatised energy and water sector expected approaches from unions and around 23 per cent of the retail sector. The number of businesses expecting approaches is far more than predicted.
Two out of five respondents said they recognised unions for collective bargaining.