The Group of Seven club of rich powers should lose its place as the lead authority on the global economy to the broader G20 grouping, which includes the world's biggest developing nations, a former World Bank official said.
In a paper for the Washington-based think-tank The Brookings Institution, Johannes Linn wrote that China's absence from the G7 was one illustration of a "glaring gap in global governance".
Linn, who until August was World Bank Vice President for Europe and Central Asia, said a more appropriate bloc was G20, which includes developing giants such as China, India, Russia and Brazil as well as the G7.
"In a world where the G7/G8 economies still appear so dominant, it may be difficult to grasp the degree to which the global economy is today already multipolar," wrote Linn and co-author Colin Bradford, a former chief economist at the United States Agency for International Development (USAID).
The report argues the scale, inclusiveness and diversity of the G20 give it an authority and legitimacy few could question and which the G7 lacks. Although the logistics of organising such a large group raise concern about efficiency and timely agreements, the authors said these could be overcome with rolling working parties and sub-meetings that build for summits.
G7 has its roots in the mid-1970s, when economic crises resulting from the breakdown of the post-war Bretton Woods currency system and soaring oil prices led to informal gatherings of political and financial leaders from the United States, Japan, Germany, France, Britain, Italy and Canada.
Russia was added to the annual summits in the 1990s to make it G8, but the finance teams remain among the G7 and meet four times a year - most recently on the fringes of the International Monetary Fund's Spring meetings last week.
"For the G7/G8 countries, the apparent loss in exclusivity should be more than offset by the increased relevance and effectiveness of their efforts to address issues of great global and national significance," the report said.
"For the world at large, the new G20 will mean a real and positive change from the increasingly stale and ineffective G7-G8 summits".