Royal Bank of Scotland chairman Sir Tom McKillop tonight told shareholders and staff he was "profoundly sorry" for the disastrous position in which he has left the business.

In an extraordinary speech released to the Stock Exchange, he said: "The buck stops with me as chairman and with the leadership of the group. Accountability has been allocated and fully accepted."

McKillop,b who took the chair in 2006, will retire next year. Hapless chief executive Sir Fred Goodwin stepped down today. Goodwin's departure came at a shareholders' meeting that voted through the bank's taxpayer-funded £20 billion capital-raising in what marked the final chapter of the boss's career.

The chairman, who read the speech to a packed meeting, thanked the Government for the bailout package that should save the bank's skin.

He said: "I am sorry about the very real financial and therefore human cost that those who have invested in us now feel and recognise how seriously this has impacted shareholder confidence in RBS. And I am also sorry if any of our customers have suffered anxiety as a result of the situation."

In a message to his staff, the former pharmaceuticals executive who earned £750,000 in his RBS post last year added: "But I am also acutely aware - every day - of the fact that thousands of our employees past and present have believed so much in their company that they gave more than their labour to it.

"They bought shares, share-save options and buy-as-you-earn, often from very modest incomes. They were proud of what RBS achieved and were delighted to be associated with it. The anxiety they now feel is of great concern to the board, the executives and me.

"I want there to be no doubt that the overwhelming majority of RBS employees should neither feel nor bear any responsibility for this situation. They have done, and they continue to do, an outstanding job."

While making his apologies, however, McKillop claimed that he and the board had always acted on the information they had at the time, blaming the bank's troubles on external factors in the financial markets. The collapse of Lehman Brothers had been the start of the disastrous decline of its solvency levels, he said. Critics argue the bank's implosion was due to Goodwin's overly aggressive risk-taking, particularly his pressing on with the multi-billion-pound takeover of ABN Amro even after the credit crunch had begun.

McKillop today claimed of the takeover: "Based on what we knew then, that was a reasonable course for us."

He added that even without that deal, RBS would still now be needing to raise more money, just like its rival UK banks. He thanked the Government for coming forward with its bailout package, which he said was vital for RBS to survive.

"We are therefore grateful for the Government's intervention," he said.