Natural disasters, international terrorist attacks and a steep rise in oil prices top the list of the biggest near-term risks that concern US business executives, according to a study by Marsh, the insurance broker, that will be released on Thursday

But the one hundred-plus CEOs and senior directors of Fortune 1000 companies surveyed played down the risk of a housing market collapse or a pandemic disease within a decade.

Harvey Pitt, former chairman of the Securities and Exchange Commission, and a council member of Marsh's newly created Center for Risk Insights, which conducted the survey, called the findings "distressing".

"You get a clear sense from people that there are real problems lurking, and yet the hope for CEOs is 'not on my watch'," he said. "The CEO may be hopeful that he or she can escape [dealing with the issue] but the board of directors, whose intent is to have a lengthy watch, will not be as fortunate."

Half the executives surveyed do not believe climate change with long-term environmental and economic impacts is likely. Less than one-third consider a pandemic with high mortality as having a severe impact on their business.

According to the survey, executives' main reasons not to prepare for particular crisis situations are that the risk is not perceived as relevant to their organisation, is too unwieldy to manage or too costly to mitigate.

"Shareholders have a right to assume that business leaders have made an effort to understand the implications of emerging threats and have taken steps to address these challenges," Mr Pitt added.

The study showed more than half of companies had made efforts to prepare for the possibility of natural disasters or a steep rise in oil prices. Roughly four in 10 said their company had prepared for terrorist attacks or a pandemic disease.