The Bloomberg Professional terminal, located in the Subotnick Financial Services Center, has credit ratings on companies including international banks. You will find ratings by Standard & Poor’s, Moody’s, and Fitch (if tracked) for each company.
After you type in the ticker for a bank, for example, you can next type the command, CRPR , to get a credit rating profile. The credit history on these companies seems to go back as far as 10 years.
You can use the command, RATC , to get an alphabetical list of companies with their recent credit rating revisions as well as historical ratings (over 4000 companies). You can then sort from this point on.