Other key developments on another day of market turbulence have included:
The UK government has announced a package of measures aimed at rescuing the banking system that makes available £400bn ($692bn) of fresh money.
US Treasury Secretary Henry Paulson said that more financial firms were expected to fail in the US despite a $700bn government bail-out programme.
The British government said all UK savers with accounts in the closed Icelandic internet bank Icesave would get all their money back.
Italy also unveiled details of a banking rescue plans that will involve the government taking stakes in failing banks.
ING Direct announced it was acquiring more than £3bn of deposits held by British savers with Icelandic-owned banks Kaupthing Edge and Heritable Bank
Austria and Hungary became the latest countries to fully guarantee savers' deposits
The other central banks that took part in the co-ordinated rate cut were those in Canada, Sweden, and Switzerland. China also reduced its interest rates, the second time it has cut its key rate in less than a month.
Henry Paulson on the strain facing the financial markets
"The co-ordinated interest rate cuts got the 'thumbs down' from equity markets, suggesting we have not yet turned the corner in this financial crisis," said analysts at Capital Economics.
Earlier in Asia, Japan's Nikkei had closed down 9.4% at 9,203, its lowest finish since June 2003.
Hong Kong's Hang Seng index closed 6.2% lower. India's main index fell 8% at one point but eventually closed down 4.3%.
Markets in Australia, China and Taiwan were among other fallers.
Russia's Micex exchange has suspended trading until Friday, after the index dropped more than 14% in the first half-hour of trading.
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