The European Central Bank said that it will undertake a comprehensive assessment of six banks in Bulgaria as part of the process of establishing close cooperation on supervision with the country's central bank. ECB will test the four largest lenders in Bulgaria in terms of assets - UniCredit Bulbank, DSK Bank, United Bulgarian Bank (UBB) and First Investment Bank (Fibank), as well as lower-ranked Central Cooperative Bank (CCB) and Investbank, ECB said in a statement on Monday. The assessment of the six banks includes an asset quality review and a stress test."The exercise will start in November 2018 and its aggregate and bank-by-bank results are expected to be published in July 2019. The cut-off date for the exercise will be 31 December 2018," ECB said. Bulgaria's finance ministry said last month it had sent a request for close cooperation with ECB on banking supervision as part of the country's commitments taken in a letter of intent for participation in the ERM II, the euro's waiting room. Bulgaria intends to enter the mechanism for close cooperation and ERM II simultaneously.