China's big State-owned banks have announced plans to raise $43.5 billion in on- and offshore Tier 2 capital by the end of 2015.

Agricultural Bank of China plans to sell 50 billion yuan of Tier 2 securities, Bank of Communications is in for 40 billion yuan and China Construction Bank for 60 billion yuan. ICBC is eyeing a total of 60 billion yuan, while Bank of China will make a play for the same.

All that makes for a total of 270 billion yuan in Basel III compliant bonds that will hit the market - more than from any other single country.

Lenders are issuing to replace old-style Tier 2 bonds that are about to mature and hold yields down, Chan said.

"If you don't repay bondholders, the yield will increase automatically, so the best way is to issue bonds at a similar or lower rate to repay the earlier one."

A total of 93 billion yuan of subordinated bonds from China's commercial banks will mature next year, according to China Central Depository & Clearing, a State-owned clearinghouse for onshore bonds.