The ECB examined valuations used by euro zone banks in its comprehensive assessment and published the results on Sunday.

The assessment results show that Commerzbank's corporate loan book to be worth 1.19 billion euros less than stated by the bank itself a the end of last year, making it the biggest single asset class at Commerzbank to suffer under the ECB's review.

Commerzbank passed the overall stress test by a comfortable margin, posting a common equity tier 1 ratio of 7.96 percent in the hardest part of the assessment, compared to a minimum requirement of 5.5 percent.

(Reporting by Thomas Atkins; Editing by Arno Schuetze)