Forty-six countries had joined or applied to become founding members of the China-led Asian Infrastructure Investment Bank (AIIB) by Tuesday's deadline.

The final list of founding members will be decided as early as April 15. After that date, countries can apply to join as ordinary members.

Productive negotiations were held among the potential founders on the new bank's draft rules, officials said.

Jin Liqun, secretary-general of the AIIB's multilateral interim secretariat, reported on the latest developments regarding the bank's preparatory work to representatives from 29 would-be founding members who attended a working conference Monday and Tuesday in Almaty, Kazakhstan.

The AIIB's charter is expected to be finalized and signed in the middle of the year, and the bank will be set up by the end of the year.

At the meeting, representatives also discussed governance, procurement and environmental and social frameworks, according to a statement on the Chinese Finance Ministry's website. No further details were given.

The bank will be a multilateral institution aimed at funding infrastructure and other productive sectors in Asia. Major Western economies have flocked to join, including the four largest in Europe — Germany, France, the United Kingdom and Italy — along with Australia, South Korea and Brazil. Sweden and Kyrgyzstan are the latest countries applying to join the AIIB.

The AIIB has authorized capital of $100 billion, and its initial subscribed capital is expected to be about $50 billion. Potential founding members have agreed that GDP will be the basic parameter in determining share allocation among member countries.

While more than 40 countries have joined or applied to join the bank as founding members, experts said some important issues will soon need to be resolved.

Rod Wye, associate fellow at Chatham House, a think tank in London, said those included rules for governance and how capital is divided.

There are also questions over how successful the bank will be in providing loans, who receives the loans, and the types of companies that benefit from them, Wye added.

By Tuesday's deadline, Japan and the US were the ones noticeably missing among the applicants. The US has shifted its tone from questioning the AIIB's governance standards to expressing hope for the AIIB to work with World Bank and ADB, the two institutions the US wields outsized influence over.

Eswar Prasad, a senior fellow at the Brookings Institution and a former chief of the International Monetary Fund in China, said the US will have to come to terms with a rival that is finally maturing and showing that it can provide constructive leadership through international engagement.

"The AIIB's stated objectives – financing infrastructure projects in Asia – means that it will complement rather than directly compete with the work of other multilateral institutions," said Prasad, a professor at Cornell University.

"The AIIB is creating a governance structure that removes many of the problems present in existing multilateral institutions," he said. "It could therefore set a better standard for international governance and catalyze reforms in the existing institutions."

Shen Dingli, a professor of international relations at Fudan University, said China should just lead the AIIB and not dominate it.

"Make AIIB a high-standard institution, though not necessary employing the same standards as World Bank or ADB," Shen said.

"Even without AIIB, China is in a position to increase its contribution to infrastructure development abroad," said Zha Daojiong, a professor of international political economy at Peking University.

"With AIIB, China sends out an unambiguous preference for multilateralism, Zha said. "This is healthy for all major powers around the world."

Contact the writers through zhaoyinan@chinadaily.com.cn