PORTO, Portugal (AFP) -- With no end in sight to the current credit crisis, Europe's finance chiefs have launched a drive to lift the shroud of opacity over the rarefied world of high finance, which they blame for the turmoil.

European finance ministers and central bankers called on Friday at a meeting in Porto, northern Portugal, for more transparency in the financial system in a bid to restore confidence to nerve-wracked investors.
Roller-coaster volatility has gripped financial markets since early August as concerns about high-risk home lending in the United States have prompted investors worldwide to reassess their overall risk exposure.
In response, Europe's finance chiefs ordered a high-level panel ""to review alongside our international partners how to improve transparency of complex financial instruments, of institutions and vehicles.""
Amid the recent market turbulence, some financial institutions have discovered that they were bearing more risk than they thought due to often opaque repackaging of complex financial instruments.
Major British mortgage lender Northern Rock had to be bailed out by the Bank of England this week as banks clamp down on lending to each other on fears that some counterparts are overloaded with risky loans they cannot handle.
In the wake of the Northern Rock crisis, British finance minister Alistair Darling called for ""international action"" to drive out risks to stability in the banking sector.
""International action is needed to ensure that in the future we can reduce the risk of this sort of turbulence occurring again,"" Darling said on the sidelines of a meeting.
Darling called on the Group of Seven richest countries to review regulation of the banking sector and credit rating agencies, which have been blamed for not sounding alarms about the weakness of some financial institutions.
Separately, German Finance Minister Peer Steinbrueck said: ""France and Germany want to raise together this question of transparency in the international finance system during the next G7 meeting in Washington.""
He too focused on the role of credit rating agencies in the current crisis, which are facing growing criticism for not having sounded alarm bells about the riskiness of some highly complex finance.
""What I'm particularly interested in is to what extent the rating agencies participate in the conception of structured financial products and to what extent the same agencies participate in their rating,"" he said.
EU Services Commissioner Charlie McCreevy, who guides European policy on the financial sector, warned that ""investors have not understood the risks that they have taken on"" due to the extreme complexity of some of the financial products they have bought.
Greater transparency was needed because ""supervisors need to see where the risks really lie,"" McCreevy said.
The finance ministers and central bankers said in a joint statement that although Europe's ""regulatory and supervisory rules are sound,"" they ""should reinforce framework further.""
But while Europe needed to bolster its oversight of the financial services industry, McCreevy warned against over-reacting and said that ""it would be a major mistake to rush out with new ideas for regulations.""
He also said that he did not expect to see during his ""life-time"" a single European banking regulator even though Europe's banks are increasingly active across borders.