Mr Casey resigned from his post yesterday after just 20 months in the job.
This leaves just AIB’s Eugene Sheehy as the only chief executive of a listed bank not to announce his resignation or early retirement.
Mr Casey’s resignation follows the departures of Irish Life and Permanent finance director Peter Fitzpatrick and treasury head David Gantly after a board meeting on Thursday night.
Irish Life said this week it supported Anglo with deposits totalling €7.45 billion in September to help the bank “in the face of an unprecedented threat to the stability of the Irish financial system”.
The transactions may have created a “false impression” about Anglo’s deposit base, according to Finance Minister Brian Lenihan.
The bank said Mr Casey had offered his resignation after the Thursday meeting, but that it wasn’t accepted by the board.
However, yesterday afternoon it said Mr Casey insisted that his continued presence would be a “distraction” having reflected on the situation with his wife and family. His resignation was accepted, but he will remain on as acting chief executive until a replacement is found.
The resignation came after Mr Lenihan called Irish Life chairwoman Gillian Bowler and other directors to a meeting yesterday after the initial rejection of Mr Casey’s offer to resign.
Ms Bowler will remain on in her position, but said she accepted Mr Casey’s resignation with the “utmost regret”.
“Denis Casey is a man of the highest integrity and honour. I have always held him in the highest regard as a colleague and as a friend and I know that his decision today — as always — has been prompted by his dedication and loyalty to the company,” she said.
Mr Lenihan welcomed Mr Casey’s decision to resign saying it is “an essential first step in repairing the reputational damage done to the Irish financial system by this transaction”.
Anglo Irish chairman Donal O’Connor said yesterday that the board has begun a “comprehensive review” of the transactions.
The board is “fully committed to ensuring that, as a state-owned bank, the highest standards of corporate governance and business ethics be observed,” he said.
Meanwhile, the central bank said transactions between Anglo and Irish Life & Permanent could not have provided liquidity for Anglo.
“These transactions are inconsistent with the substance of the discussions that the central bank has had with our domestic institutions,” a spokeswoman said.