Global shares have fallen again as concerns about world credit conditions - driven by problems in the US mortgage sector - continue to worry investors.

London's FTSE 100 fell 1.4% to 6,058 points by 1200BST while Japan's Nikkei-225 index dropped 2.2% to finish at its lowest close in eight months.

On Tuesday, the Dow Jones lost 1.6% to 13,029 points and the Nasdaq fell 1.7%.

The falls came despite the Federal Reserve saying it would inject more funds into financial markets if needed.

To ease fears over available credit, sparked by the downturn in the mortgage sector, the Fed has already pumped billions of dollars of emergency funds into the banking system in recent days - twice on Friday and again on Monday.

The European Central Bank (ECB) and the Bank of Japan have made similar moves.

'Watching carefully'

Worries about a slowdown in US consumption were driven by retail giant Wal-Mart lowering its profit forecast, after saying that its customers were straining under economic pressures such as high oil prices. Its shares fell 5.1%

Also down sharply was another retailer, Home Depot, which lost 4.9% after warning that its profits would fall this year as a result of the sluggish housing market.

Concern over the strength of US spending, and its impact on Asian exporters, meant that the Nikkei ended the day down 369 points at 16,475.61, its lowest level since December 2006.

In Hong Kong the Hang Seng closed down 2.9%, while in Europe France's Cac 40 index lhad ost 1.5% and Germany's Dax index slipped 0.3% in morning trading

Japanese Prime Minister Shinzo Abe said that despite the fall in share prices, the economy was still solid.

"I think the Japanese economy has remained strong but I will be watching it carefully," he said.

Recent financial market volatility has been triggered by the US sub-prime mortgage sector, which offers higher-risk loans to people with a poor credit history.

As US interest rates have risen and the housing bubble has burst, a growing number of sub-prime borrowers have defaulted on their loans prompting extensive financial difficulties for a number of investment funds with heavy exposure to the sector - and triggering fears of a wider financial crisis.

While some estimates say $300bn in loans could be at risk, one of the biggest worries for investors is not knowing the eventual scale of the problem.