As if the continent didn't have enough financial worries, McGraw Hill Financial's Standard & Poor's has cut its ratings on a trio of European banks. The agency notched down the long-term counterparty credit ratings for Barclays (BCS 0.56%), Credit Suisse (CS), and Deutsche Bank (DB -0.46%). All were reduced to "A" from the previous "A+". 

In the press release announcing the news, Standard & Poor's said the chops were based on its concern about "the increasing risks that Europe's largest banking groups active in investment banking face as regulators and uncertain market conditions continue to make operating in the industry more difficult."

The news wasn't all gloomy, though. The agency removed the long-term rating on Deutsche Bank from CreditWatch, where it had been placed, with negative implications, at the end of March.

Additionally, Standard & Poor's reaffirmed its existing long- and short-term ratings on fellow European banking incumbent UBS (UBS 0.49%). That bank maintains its "A" and "A-1" designations, respectively.