By Bill Wilson
BBC News business reporter at the CBI conference in Birmingham
Police are working with businesses to improve their security
British business faces a number of security threats to its well-being.
From al-Qaeda style terrorist atrocities and animal rights extremism to computer hacking, trespass, and shoplifting.
Delegates at the Confederation of British Industry (CBI) conference heard Eliza Manningham-Buller, director-general of MI5, warn: "There is a serious and sustained threat of terrorist attacks against UK interests at home and abroad, including the business community.
"Across the UK, private companies are working with the (security) service and the police to increase resilience and strengthen the capability of the private sector to stay in business in the face of threats or actual attacks," she added.
Her warning came as the CBI revealed a survey of its members showing that two-thirds of companies upgraded their security last year in the face of increasing concerns.
Mrs Manningham-Buller continued: "My message is to broaden your thinking about security issues. A narrow definition of corporate security including the threats of crime and fraud should be widened to include terrorism, and the threat of electronic attack.
"In the same way that health and safety and compliance have become part of the business agenda, so should a broad understanding of security.
"Considering it should be an integral and permanent part of your planning and statements of internal control - do not leave it to the specialists."
She said all firms should have sophisticated business continuity plans in place, which are discussed at board level regularly.
"The threat is current and real. It affects us all and you, supported by us, have a key role to play."
Many of the firms questioned in the CBI/Qinetiq security survey said greater openness between government and UK business would make the biggest difference to Britain's ability to do business in the current security climate.
The types of security incidents causing most current concern to UK firms are terrorist actions, environmental terrorism, and computer hacking.
Some bigger companies also highlighted the damage done and threats posed by animal rights campaigners, who have broadened their attacks to "secondary" targets.
"Animal rights extremism and the threat it poses to ordinary people going about their daily lives is the most obvious example," said CBI director-general Digby Jones.
"People have the right to protest but not in a way where they terrorise a legitimate business. Not where kids are terrorised at school and paint is thrown over cars.
"It is an attack on democratic capitalism."
One businessman said extremist activity had forced him to reconsider some contracts.
Steve Hindley, chief executive of Devon-based Midas Group, which owns a construction firm, said: "My companies won't get involved in construction of certain research establishments, because of what happened to one of my competitors."
He was one of the many business people who had welcomed the Home Secretary's establishment of a National Extremist Tactical Co-Ordinating Unit earlier this year.
Superintendent Steve Pearl, from Cambridgeshire Police, who heads the unit said its role was to provide advice and guidance to companies.
"There has been an increase in extreme domestic activity, and we are trying to come up with more effective tactical solutions, working with business organisations and government agencies."
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He believed the vast majority of animal rights campaigners were law-abiding.
But among 10,000 protestors there may be 100 extremists, he said, who would carry out "disruptive and intimidatory behaviour".
His comments backed up those of Dame Pauline Neville-Jones, chairman of defence and security experts Qinetiq, who warned that there were those with "malign intentions" willing to target UK business for whatever reason.
"It is not just terrrorism," she said. "There are extremists and there are electronic attacks. The question for many firms is 'have I done everything I could do?'".
She said security was more than just physical gates and barriers but making full use of electronic and technological defence systems.
"The UK has the chance to take the lead here," said Leslie Stretch, UK managing director of Sun Microsystems.
One UK firm taking its security responsibilities is Sheffield-based FM Informatics, which is cataloguing US federal government and Presidential archives.
"We take our security very seriously, as we could be perceived by some groups as being US-connected," said chairman Professor Anthony Fretwell-Downing.
"If someone made a successful electronic attack on us they could play havoc and we could be out of business if we were unable to repel them. We also take physical security in our buildings very seriously too."
According to the CBI, two in three companies now have a Chief Security Officer, with one in five actually on the board.
The CBI's Digby Jones said four out of five firms also now wanted to see a specialist police section to deal with crimes against business.
The head of security at British American Tobacco, David Burrill, warned that post-11 September, business faced new challenges and needed a more modern approach.
"Corporate security is to companies what national security is to nations," he said.
"It is extremely wide-ranging, and extremely important, not just some esoteric add-on."