NEW YORK ( TheStreet) -- European bank stocks were mixed after Eurozone leaders agreed that the European Central Bank would begin regulating many of the continent's most important banks, beginning in March. European finance ministers agreed early on Thursday on a Single Supervisory Mechanism (SSM), under which the European Central Bank would begin its supervisory role in March, with national parliaments deciding on whether or not to submit the new unified bank regulator. ECB president Mario Draghi said in a statement that unanimous agreement among members of the European Union's Economic and Financial Affairs Council marked "an important step towards a stable economic and monetary union, and towards further European integration." The agreement will also pave the way for eurozone nations to bail out troubled banks. German chancellor Angela Merkel said before the Bundestag on Thursday that the significance of the agreement for the SSM "could not possibly be overestimated," according to a Deutsche Welle report. Merkel also said she was looking for further agreements before the end of the European Leaders' summit in Brussels on Friday, including "concrete measures today and tomorrow that focus on how we can achieve this increase in competitiveness." European bank stocks were mixed in U.S. trading. German bank stocks were lower, including Deutsche Bank ( DB), which was down over 2% in midday trading, to $43.66, while American depositary receipts of Commerzbank AG ( CRZBY) were down 2% to $1.85 Meanwhile, shares of UBS ( UBS) were down slightly, $16.33, while Credit Suisse ( CS) was up 1% to $24.78, BNP Paribas was up slightly to $43.22, and HSBC ( HBC) was up slightly to $51.96.