Bankwest's credit rating has been upgraded to AA/A-1+ by Standard & Poor's following its successful acquisition by the Commonwealth Bank of Australia.
Managing Director Jon Sutton said Bankwest now had the same credit rating as the CBA, which last week received regulatory approval to acquire Bankwest's retail and business units from HBOS Plc.
Bankwest is one of only 19 banks globally to have the AA rating after it was upgraded from A+/A-1.
"This is a vote of confidence by Standard & Poor's in CBA's acquisition of Bankwest and means our customers will have even greater investment grade security," Mr Sutton said.
"Standard & Poor's says it believes Bankwest will be a core subsidiary of the CBA and will be operationally integrated in terms of funding, risk management, system, and processes.
"Moreover, Standard & Poor's expects BankWest will be a material part of the CBA group, representing more than 10% of total group capital."
AA means Bankwest's capacity to meet its financial commitments is "very strong".
Mr Sutton noted Standard & Poor's considered the CBA "is adequately placed to manage integration challenges related to the acquisition".
