Banks in the euro zone expect to continue toughening their credit rules for firms and households in the first part of 2010, despite hopes the tightening cycle had peaked, the European Central Bank said on Friday.

A net 4 percent of banks said they saw themselves tightening credit standards to firms in the first quarter compared with the net 3 percent that toughened lending requirement in the fourth quarter of 2009.

"The net tightening of credit standards on loans to non-financial corporations declined to 3 percent in the last quarter of 2009... which was somewhat above the expectation, at the time of the previous survey round," the ECB said in its latest quarterly Bank Lending Survey.

"Looking forward, euro area banks expect some further tightening of credit standards on loans to NFCs in the first quarter of 2010, with net tightening potentially worsening slightly, to 4 percent," it added.