Business has welcomed a surprise announcement by Gordon Brown on tax cuts for big companies.

With the budget not taking place until April 17, the measures announced by the Treasury include a research and development tax credit for large companies and an exemption for gains and losses on substantial shareholdings to prevent restructuring decisions being made for tax reasons.

Also announced was a new regime for providing relief to companies for the costs of intellectual property, goodwill and other intangible assets.

The measures to support big business come amid restlessness on the Labour backbenches after Stephen Byers' retreat on compensation for Railtrack shareholders.

The chancellor said the government was continuing to promote rising productivity levels.

"In our first term we put stability and employment creation first. In our second term, as we prepare for the sixth budget we are able to build on this platform of stability and employment creation and our energies must continue to be directed to promoting enterprise and investment and raising our country's productivity," he said.

The announcement came in answer to a written parliamentary question, prompting anger from other parties about the lack of debate on the measures.

But the British Chambers of Commerce welcomed the plans.

David Lennan, director general of the BCC, said: "Today's tax measures will aid big business competitiveness, by bringing our tax law in line with, and even going beyond, what is already available in other countries. In its desire to improve productivity and create a high value-added economy in the UK the government is right to use tax policy to encourage innovation and to smooth the transfer of intellectual property."

But he said the government should be equally generous with help for small businesses.

"A similar package of support of the order of £500 million plus would go a long way to satisfying our own Budget demands for supporting small employers and promoting investment and innovation in small manufacturing firms."

Shadow chancellor Michael Howard said the government had not proved to be a friend of business in the past.

"We welcome any measures that genuinely help business, but since 1997 Gordon Brown has claimed every year his Budgets would help, and they haven't. In fact the chancellor has piled new burdens on to business, making it more difficult for companies to win orders and create jobs," he said.

He pointed to the imposition of 4642 regulations last year alone and tax increases on company car drivers.

"After this record over five years, to suggest that Gordon Brown is now going to lower business taxes is rather like a villain taking someone's wallet, extracting the notes, and returning the wallet with some small change still inside."

Matthew Taylor, Liberal Democrat Treasury spokesman, said it was "outrageous" that the chancellor had not made a statement in the Commons on the news.

"Once again Labour care more for spin than accountability. Business will welcome a tax cut but not the further complication of the tax system which Gordon Brown has introduced once again."