Punjab National Bank has received upgrade in rating on Basel III AT1 Bonds from 'IND AA/Stable' to 'IND AA+/Stable' while affirming its Long-Term Issuer Rating at 'IND AAA/ Stable', Short-Term Issuer Rating at 'IND A1+' and ratings on Basel III Tier 2 Bonds & Senior Infrastructure Bonds at 'IND AAA/Stable'.