This is the first time the award scheme, which is now in its third year, has been extended beyond the UK.
The move is part of a wider drive to urge UK firms to use their website to present essential company information to their shareholders in a readily accessible form.
IRS director-general Andrew Hawkins said: 'As standards of corporate disclosure become ever more demanding, competition for these awards will inevitably be fiercer than ever.'
Hawkins unveiled the move to invite European firms ahead of the launch of the single market for financial services in 2005.
Nominations can be submitted online at www.irbestpractice.org. The awards dinner will be held on 10 April 2003. They are backed by the Department of Trade and Industry and the London Stock Exchange.