AIB shares fell again today after yesterday's steep losses as Finance Minister Michael Noonan advised against investing in the State-owned bank.

Mr Noonan said yesterday that the structure of the bank's shares meant it was considerably overvalued at around €55 billion.

The Minister said this valuation would need to change before the bank returned to private ownership, adding that those investing in the bank before this happened would lose money.

After falling as much as 20% in earlier trade, shares in the bank were 4.5% lower by the close of business in Dublin.

The bank shares had also slumped over 20% at one stage yesterday. 

Blog: Noonan pricks the bubble in AIB shares

The low price of an AIB share makes it particularly susceptible to large percentage changes.

Mr Noonan said yesterday that officials at his department, along with others, are working on a blueprint to get AIB back into private ownership.

He said he was not announcing the imminent sale of AIB, but said the process of setting out a blueprint for that to happen has started.

The process would take a number of years, the Minister said, adding that there will be further announcements on it leading up to Christmas.

In a statement to the stock exchange this morning, AIB said it noted the media coverage of the Minister for Finance's comments in relation to the bank. 

It said that as previously stated, AIB has about 523 billion ordinary shares in issue, of which 99.8% are held by the National Pensions Reserve Fund Commission.