TOKYO - Concerns that China's large stake in its new initiative of a multilateral development bank would lead to an unchallengeable status for the country within the framework have not abated since the concept of the Asian Infrastructure Investment Bank (AIIB) came into being.

However, a Japanese economist, who calls on his country to join the AIIB at an early date, said it is unnecessary to worry about the shareholding structure of the bank at a time when details related to the bank's governance and stake structure are still pending.

Kiyoyuki Seguchi, research director of the Canon Institute for Global Studies, told Xinhua during an exclusive interview Tuesday that as the AIIB is open to all, China's shareholding will gradually decline with more countries being included in the multilateral development bank and the trend would also be acceptable to all members.

He further pointed out "It is a convention that countries should negotiate first and then decide whether or not to join an international mechanism," adding it is premature to be concerned over transparency and governance issues.

"Compared to the shareholding structure, the way members use their stakes will be more important after the structure is settled, " the expert said.

"However, China's economic scale is so large already, and, according to the International Monetary Fund, its economic scale will be 2.3 times as much as Japan's this year, so it is natural for China to have its stake as 2.3 times as large as Japan's," if Japan decides to join the AIIB, said Seguchi.

The former Rand Corporation international visiting fellow suggested that large shareholding proportions will not necessarily lead to a monopoly since China understands that credibility is significant for the AIIB and it would plunge if China makes decisions at its own will based on its large share.

China has reiterated on different occasions that the AIIB will uphold high standards and learn from the best practices of existing multilateral financial institutions.

Jin Liqun, secretary general of the interim multilateral secretariat of the AIIB, said Saturday that all members will be committed to building a bank which would be lean, clean and green. "Lean is cost effective; clean, this bank will have zero-tolerance on corruption; green means it's going to promote the economy," Jin detailed.

"If China pays enough respect to and follows the traditions of international developmental banks well enough in terms of transparency, governance, environmental protection and energy saving to manage the AIIB, every member will support and respect China's proposals," Seguchi said.