Firms afraid of attacks from animal rights activists, computer hackers or terrorists have spent £1m on extra security this year, says a new survey.
Firms are protecting themselves against a range of threats
The Confederation of British Industry (CBI) survey of 100 top companies suggests most of them have shaken up their security arrangements.
And two-thirds now employ a chief security officer.
The CBI says the government could boost confidence by being more open about its contingency plans.
Question of confidence
The organisation says the bill for investment in security is significantly higher than it was five years ago and some of the new security chiefs even had places on firms' board of directors.
Despite the extra security measures, 60% of those questioned in the Mori telephone poll said they were
concerned about their firm's level of preparedness for an attack.
CBI director general Digby Jones said: "Business Britain understands the meaning of risk and is working hard to calibrate the additional risks posed by security.
Digby Jones says policing is inadequate against some threats
"But the risk assessment process in a business would be much improved if there was greater transparency from government and other key agencies.
"Business needs to have more confidence that it is getting its contingency planning right".
Mr Jones also complained policing to deal with some threats, including those posed by animal rights activists, had been inadequate.
"In a democratic society, companies and everyone that works for them must be
protected from those who seek to prevent lawful business activity," he said.
The problem of business security is on the agenda in
the opening session of the CBI national
conference in Birmingham on Monday.
Dame Pauline Neville-Jones, chairman of security technology specialists QinetiQ, said companies looked to the Home Office, police and private specialists for security advice.
She suggested a coalition of agencies was needed to provide commonsense guidelines on the best measures.
"It is not surprising that six in 10 companies have residual concerns about their preparedness," said Dame Pauline.
"In the absence of relevant guidelines and measures, they cannot be sure that their resources and budgets are being used to greatest effect."