That leaders from the world's leading industrialized countries - Canada, France, Germany, Italy, Japan, the United Kingdom and the United States - are expected to discuss "building the foundations of renewed trust" in Sicily, Italy, on Friday and Saturday offers a glimpse of the challenges facing the G7 amid growing concerns over global governance.

Established in 1975 by "the world's six major industrialized democracies" before Canada joined it a year later, the G7 seems to have passed the baton of international economic coordination to the G20 after the 2008 financial crisis. The G7 still accounts for more than 40 percent of the world's economy, but their combined contribution to global growth is not equal to that of China alone. And given the continuing currency and trade disputes, it is only natural for the G7 to yield place to the more inclusive G20 to build the foundations of renewed trust.

The founding of the G20, which comprises the G7 as well as BRICS (Brazil, Russia, India, China and South Africa) and other major economies, also poses a challenge to the G7's legitimacy. The co-existence of concerting mechanisms upheld by different regional economic blocs, to some extent, could deal another blow to the G7's once-dominant role now that the G20 enjoys more international credibility.