Transparency International says Chinese and Russian firms are the most likely to pay bribes when doing business abroad.
After surveying companies in 28 countries, the organisation says
China and Russia rank bottom in its 'Bribe Payers' index. Dutch, Swiss, Belgians, Germans and Japanese companies are the least corrupt.
But the group says not one of the countries surveyed was "wholly clean of bribery".
It says the most corrupt sectors are public works contracts and construction.
Agriculture was considered the least bribe-prone, while banking ranked the fourth least-corrupt out of 19 industries.
Transparency International has urged countries to ratify conventions against bribery under the auspices of the United Nations, the Organisation for Economic Cooperation and Development and the European Union.