Representatives from Africa and poorer Asian nations have been asked to attend the G20 financial crisis summit in London on April 2, British Prime Minister Gordon Brown said on Friday.

Brown has asked the New Partnership for Africa's Development, the Association of South East Asian Nations and the African Union Commission to send delegates to the summit.

That will give a voice at the meeting of leading developed and emerging economies to less wealthy countries across Africa and Asia such as Nigeria, Cambodia and Vietnam.

One of Brown's key aims for the summit is to make international institutions such as the World Bank and International Monetary Fund more representative by giving more power to developing nations.

"The global economic challenges we face need to be met with decisive action if we are to secure jobs, restore confidence and reinvigorate growth," Brown said in a statement.

"To be effective in addressing this global crisis we have to bring in partners from across the world.Having this mix of countries and international organisations present not only reflects the new reality of the global economy but will also make any action we take more effective."

However, while most nations agree with the principle of giving more of a say in the governance of world finance to smaller economies, it is far from clear whether there is any appetite to make it a reality in April.

Brown's office said it had also issued formal invitations to leaders from Argentina, Australia, Brazil, Canada, China, current European Union presidency holders Czech Republic, France, Germany, India, Indonesia, Italy, Japan, Mexico, the Netherlands, South Korea, Russia, Saudi Arabia, South Africa, Spain, Turkey, the United States and the EU Commission.

The April 2 summit is likely to mark Barack Obama's first trip to Europe as U.S. President.