Asked by the Sunday Tribune whether the regulator would, in light of radically changed market conditions, be adjusting its approach to overseeing the thousands of debt securities listed on the ISE, a spokeswoman would only say that "taking account of market trends. . .form part of our ongoing interaction with financial institutions".

Meanwhile, European internal market commissioner Charlie McCreevy has written to Eddy Wymeersch, chairman of the Committee of European Securities Regulators (CESR), seeking a meeting in September to fashion a "specific response" to the ongoing liquidity crisis.

According to an adviser to McCreevy, the commissioner wants to discuss how the overseeing of debt securities can be reviewed and strengthened.

It is understood that "stake-holders" in the regulatory process will attend the meeting, but it was unclear by late Friday if the Irish financial regulator, which is a member of CESR, would attend.

McCreevy has also called for an investigation of the role that credit rating agencies such as Moody's, Fitch, and Standard & Poors have played in underestimating the levels of risky debt rolled into investment-grade bonds that they have helped structure.

Fianna Fail MEP Eoin Ryan echoed the commissioner's concern on Friday in a request for public hearings into the operations of credit rating agencies to be carried out by the European parliament's economics committee.

Ryan cautioned against blaming regulators for problems in the markets, however, although he didn't rule out their becoming subject to investigation in Brussels.

"We're going to start with the credit agencies and see if there are more questions after that, " he said.

The current turmoil in the markets has been triggered by defaults on subprime loans been extended to poor credit candidates in the US. These loans had been packaged . . . or securitised . . .together with higher-grade debt in bonds that were then sold to investors.

As the debtors have defaulted, the prices of many of these bonds have collapsed, seizing up the credit markets and depressing share values.

The Irish stock exchange is one of the world's leading locations for listing this kind of structured finance. The Financial Regulator and the ISE share responsibility for approving the prospectuses of the debt securities vehicles that list here. In the first half of this year, the exchange approved 552 new debt securities, a 30% on the same period in 2006.