HDFC Bank has appointed external law firms to independently review the issues mentioned in the resignation letter of former part-time chairman Atanu Chakraborty which put the private lender on a back foot.

The lender on Tuesday ‌said it was hiring both domestic and international firms to examine the letter "to reinforce ⁠the robust governance standards of the bank".

The law firms have been advised to provide their report within a reasonable period of time, the private lender further stated in an exchange filing.

Two domestic law firms and one US-based law firm have reportedly been appointed to review the resignation letter of ‌Chakraborty.

The domestic firms Trilegal and Wadia Ghandy & Co have been asked to report on the governance standards followed at the bank, Reuters reported.

The firms will study minutes of past board meetings to see if there ⁠is any truth in the differences over "values and ethics" cited in the letter from Chakraborty, Reuters quoted a source as saying.

The bank will not seek legal damages from Chakraborty for the reputational damage caused, the source further stated.

The abrupt resignation of Chakraborty citing differences over value and ethics has led to the share prices of the bank plummeting and raised governance concerns. 

Reiterating that there were no material concerns, the country’s largest private lender had earlier clarified that Chakraborty had not mentioned “any happenings and practices which were not in congruence with his personal values and ethics".

The Reserve Bank of India (RBI) said last week HDFC Bank remained systemically important, financially sound, and professionally managed, with "no material ‌concerns on record" regarding its conduct or governance.

The RBI has approved former long-time HDFC Group executive Keki Mistry as ⁠interim non-executive chairman for three months.