But it added, "Asia's corporate bond markets remain, with few exceptions, small and illiquid," with the region's corporate funding still overwhelmingly bank-based. In addition, despite the region's pickup in bond issuance, secondary markets have low trading volume and the segment lacks investor diversity, it said.

Bond issuance in many markets is dominated by a handful of players, it said, noting that in Taiwan and Indonesia, the ten largest issuers were responsible for more than 80 percent of the total bond issuance last year.

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"The Asian bond market initiative is to promote greater investment by making it easier for the region's investors' to invest in each other's bond markets," said Thiam Hee Ng, senior economist at the ADB. "They try to work together with both market regulators and participants to harmonize rules in the region for issuing bonds," he said.



It's a change that would likely be met enthusiastically.

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"A single rule for all of Asia would be fantastic," said Kumar Palghat, managing director at Kapstream Capital. "It would make trading easier," he said, noting each country currently has its own rules and regulations and different withholding taxes.

Palghat expects the change also would make it easier to develop benchmarks as well as create a yield curve with similar maturities. Currently, "it's difficult because when you look at all the issues, they are all in different currencies and denominations. The covenants are not the same," he said. "It would make liquidity a lot better and transparency a lot better."