Prime Minister Silvio Berlusconi said on Monday that Italy would host leaders of the G20 at the end of a G8 summit in Sardinia in July and that their talks would focus on new rules for the financial system.

"We will have the G20 as well on the third day of talks at La Maddalena (in Sardinia)," he told a conference near Milan.

"On this occasion we will prepare a legal system, new rules to stop the phenomenon of excessive securitisation in the financial system, the use of derivatives that led to this crisis," said Berlusconi. Italy currently chairs the G8.

A senior Italian diplomat told Reuters in January that Italy would be prepared to expand the G8 summit to include the G20, which is chaired by Britain, if there were a need after the April 2 summit of the G20 in London.

The G8, grouping the United States, Japan, Germany, Britain, France, Italy, Canada and Russia, tackles global challenges from the economy to the environment.

The G20, made up of the top 19 economies plus the European Union, has the task of reviving growth and reforming the financial sector and oversight bodies.

An Italian government source said that over the three days the G8 summit will also host the G5 countries of Mexico, South Africa, China, India and Brazil.

Other countries to be invited to the talks are Australia, South Korea, Indonesia and Algeria, Senegal, Nigeria and Egypt, the source said.

The G20 is made up of Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, Russia, Saudi Arabia, South Africa, South Korea, Turkey, the United Kingdom, the United States and the European Union.