Leaders of South Korea, Russia, South Africa and Germany on Thursday called for more efforts from governments and companies to help global economic recovery in their speeches to corporate leaders at G20 Business Summit.

Speaking at the opening plenary session of the Business Summit, South Korean President Lee Myung-bak highlighted the role of private sector in economic recovery, saying it is essential to let the business community lead economic growth down the road.

"To revitalize the economy, corporate sector should be regarded the most important player," Lee told some 120 leaders of the world 's leading companies from both developed and developing countries.

This was why Seoul launched the high-profile forum of global CEOs in connection with the G20 summit, which brought together the leaders of the world's leading high-income and emerging economies, he said.

"Although it has been the government to play a leading role in economic recovery, via fiscal spending, the public sector is now facing greater possibilities of inflation and fiscal deterioration, " Lee added, urging business leaders to take part in creating growth engines.

"Civilian corporate investment, which currently leads the development of emerging markets such as Asia and South America, will have to spread to underdeveloped regions, including Africa," Lee said.

This was aimed to broaden the production base of those nations, create jobs and eventually contribute to the long-term balance of the world economy, he said.

South Korea decided to add the development issue to the list of agenda items at the Seoul G20 meeting because narrowing development gaps between advanced nations and developing ones is an "urgent task" for the balanced world economy, the president said.

Russian President Dmitry Medvedev, while addressing the Trade & Investment roundtable session of the summit, said it was important to vitalize small and mid-sized enterprises (SMEs) for the sake of economic stabilization.

Medvedev pinpointed the role of SMEs in boosting up employment, productivity and demand, which, according to the head of Russia, all were currently at stake.

"Accordingly, it is important to revitalize the global economy, possibly via creating an environment friendlier towards SMEs," he said.

Under the goal of creating a new mechanism that SMEs could more easily approach, the G20 countries should all make efforts, said Medvedev.

The president also commented on expanding financial support to SMEs, stressing a need to make progress on the issue.

South African President Jacob Zuma urged "well thought-out rules" for the world economy and simple, transparent ways to implement them.

"Economic regions might work seriously for a common approach to foreign direct investment. At this stage, however, the world is too diverse for a common (approach) as nations face a range of development challenges," Zuma said.

Zuma said African nations were among the first to recover from the global economic crisis and grew faster than expected.

This, he said, indicated that macro-economic polices among African countries had improved so much, so that they could ride through the economic crisis quickly. And secondly, African nations, with huge potential, continued to grow with the expansion of domestic demand, he added.

Zuma also urged developed countries to fulfill their promises and agreements which they had signed before.

German Chancellor Angela Merkel said it was the time for the countries to begin discussion of a global exit strategy since reduced government spending will not impede growth.

"There is a need to think about what caused the global crisis and it was because of unsustainable growth. We must now think about ways to recover from the crisis and grow at the same time," she told a luncheon for the 120 corporate leaders.

The Business Summit was the prelude to the G20 Seoul Summit, which gathered leaders of world's major countries, including the U. S., China, Russia, France, Britain, Brazil and Germany. The Seoul summit would start later on Thursday.

Collectively, the G20 economies comprise 85 percent of global gross national product and 80 percent of world trade, including EU intra-trade.