The government has pledged to help keep Britain attractive to foreign multinationals as it hosts a global investment summit.
Senior executives are set to attend a meeting at the Treasury on the fringe of the summit this afternoon as the chancellor bids to retain - and encourage - fresh investment to restart Britain's stagnating economy.
Mr Darling is launching the first ever 'tax framework for business' which will explain the principles underpinning the government's tax policy.
Gordon Brown told the summit that the government was committed to "creating the best possible environment in which private enterprise and wealth creators can thrive".
The Treasury will consult with firms before making changes to the tax system. Visa applications will be simplified "in some cases". And an 'investors' charter' will lay out the government's "commitments" towards helping UK businesses grow globally.
"I respect that you make hard-headed decisions," Mr Brown said.
"You don't come just because it's a nice place to live; you come to Britain because it makes business sense. So I am proud to say that Britain is the first choice country in Europe for foreign investment, rivalled in the world only by America."
US software giant Microsoft has appointed Imperial College its lead academic partner for its innovation outreach programme today, in a boost for the government.
Mr Brown predicted: "I'm confident that more announcements and other commitments to invest - worth many hundreds of millions of pounds - will follow."