Global share index compiler MSCI Inc on Wednesday (Beijing time) again rejected including Chinese mainland listed A shares from its prominent emerging markets index.

"International institutional investors clearly indicated that they would like to see further improvements in the accessibility of China's A-share market before its inclusion in the MSCI Emerging Markets Index," Remy Briand, MSCI managing director and global head of research, said in a statement.

MSCI said that it would retain the option to include the A shares as part of its next market classification review in 2017.

"MSCI will monitor the implementation of the recently announced policy changes and will seek feedback from market participants," Briand said.

The MSCI decision means A shares, or stocks in the Shanghai and Shenzhen bourses that are denominated in yuan, won't be included in the widely used emerging markets index, which has about $1.5 trillion of assets benchmarked to it. Asset managers, pension funds, insurers and individual investors hold passive investments like an exchange-traded fund or mutual funds that track an MSCI index like its emerging markets benchmark.

Chinese stocks now listed on MSCI's emerging market index are all traded in either Hong Kong or in the United States. That means the world's second-largest economy makes up only about one-fourth of the benchmark index, while projected full inclusion of A shares would bring that ratio to more than one-third.

In June 2015, MSCI rejected the Chinese shares, citing uncertainty about who actually owns them and how easily investors can withdraw their money from Chinese investments.

Earlier this year, China's stock exchanges published rules that restrict arbitrary trading suspensions for Chinese stocks. Chinese officials have been pushing for the inclusion of A shares, seeing it as another step in the assimilation of China into the global financial marketplace.

Qi Bin, an official with the China Securities Regulatory Commission, said improvements to the trading-halt system were part of the Chinese government's efforts to facilitate MSCI inclusion. He also cited freer money transfers allowed by the foreign exchange regulator and greater recognition of beneficiary ownership.

Briand acknowledged that "there have been significant steps toward the eventual inclusion of China's A shares in the MSCI Emerging Markets Index".