LONDON -- World leaders pledged a huge raft of new spending Thursday and a crackdown on tax havens and excess corporate pay to step up the battle against the economic crisis.

The Group of 20 summit said more than $1 trillion would go to the International Monetary Fund and other finance and trade institutions helping struggling countries through the turmoil.

British Prime Minister Gordon Brown said that by the end of 2010, the Group of 20 developed and developing nations would have spent $5 trillion fighting the crisis and hailed what he called the start of a "new world order."

US President Barack Obama also called the London summit accord a hoped for "turning point" but acknowledged there was no guarantee that the recession would not become depression.

Outside the summit, there was no repeat of Wednesday's violent clashes by protesters angry at the economic crisis, but police made 32 arrests and four people were charged over an attack on a bank during the riots.

Obama said the G20 had agreed "an unprecedented set of comprehensive and coordinated actions," and stock markets shot up in response to the deal.

Wall Street's Dow Jones Industrial Average rose 3.45 percent and London's FTSE 100 index closed up 4.28 percent.

Even French President Nicolas Sarkozy, who had threatened to walk out of the summit, said the results were "more than we could have hoped for." German Chancellor Angela Merkel said a "historic compromise" had been made.

Before the summit, the United States and Britain had pushed for bigger stimulus spending while France and Germany had called for the focus to be put on greater regulation of the financial sector.

Neither side got everything they wanted.

The summit promised $1.1 trillion of "resources" for the IMF and other global finance bodies.

There will be $500 billion of funding, $250 billion in special drawing rights and $250 billion in trade credit.

But much of the new funding has already been promised by individual countries, including $100 million each from Japan and the European Union.

After the summit, the Organization for Economic Cooperation and Development published a list of "non-compliant" tax havens which Brown said would face immediate action, adding that "we have agreed tough standards and sanctions for use against those who don't come into line in the future."

Costa Rica, Malaysia, the Philippines and Uruguay were among the countries named by the OECD as tax havens which had not made any commitment to respecting international standards on exchanging tax information.

Brown said there would also be new rules on corporate bonuses to discourage bankers who take short term risks.

A new Financial Stability Bureau will "implement new rules on pay and bonuses on a global level so that there are no more rewards for failure. We want to impose corporate responsibility on every part of the world."

The leaders also ordered the IMF to sell billions of dollars of gold reserves to help the world's poor countries, Brown said.

He said the IMF and World Bank would undergo major reforms to reflect world changes which have seen the rise of China, India, Brazil, South Africa and other new powers.

"By any measure, the London summit was historic," said Obama. Australian Prime Minister Kevin Rudd said the accord "begins to crack down on the sort of cowboys in global financial markets that have brought global markets undone."

British newspapers hailed the deal as an important first step to recovery, while saying more needed to be done to deal with the banking crisis at the heart of the downturn.

But analysts and aid groups were not so impressed.

Howard Wheeldon, senior strategist at BGC Brokers, lamented that the package might only help prevent a deeper depression.

The G20 statement was "nothing that really softens the blow of recession -- but perhaps some things that stop it moving to depression," said Wheeldon.

Talks on the eve of the London summit were clouded by anti-capitalist protests in which one man died after collapsing. Police said bottles and other missiles were hurled at them as they tried to resuscitate the man.

Small pockets of demonstrators took to the streets again Thursday but there was no sign of the previous day's disorder.

Police threw up a ring of steel around the Excel Conference center in London's Docklands district, near the headquarters of many banks blamed for the international crisis.