PARIS (AP) -- Japan's stock index plunged into "bear market" territory Thursday, rattling other global markets, amid concerns that central bankers in the U.S. and Japan might tighten the tap of money that has driven stocks higher in recent months.
The Nikkei 225 index fell 6.4 percent to close at 12,445.38 — that's a drop of 21 percent from its high in May. When an index falls by more than 20 percent from a high, it is commonly defined as a bear market.
Japanese media reports said overseas hedge funds may be dumping the country's equities after the Bank of Japan's decision earlier in the week to refrain from additional monetary easing measures.
Market sentiment has worsened since the chief of the Federal Reserve, Ben Bernanke, said the central bank might pull back on its $85 billion-a-month bond-buying program — known as quantitative easing — if U.S. economic data, especially hiring, improves.
"Ever since talk of Fed tapering was first mentioned U.S. bond yields have edged higher and money has leaked out of emerging markets and emerging market currencies," said market analyst Michael Hewson of CMC Markets.
"Of course there is the other reason that for all of the stock market gains of recent months investors have finally woken up to the fact that current stock valuations are not supported by fundamentals in the current low-growth environment, and all the QE (quantitative easing) in the world can't address that particular issue."
Highlighting the tough outlook for the economy, the World Bank on Thursday cut its forecast for global growth to 2.2 percent in 2013 from 2.4 percent.
By early afternoon in Europe, Britain's FSTE 100 was down 1 percent to 6,233 while Germany's DAX fell 1.5 percent to 8,018 while France's CAC-40 shed 0.8 percent to 3,762.
Among notable losers was Royal Bank of Scotland, PLC, down 4.3 percent on the news CEO Stephen Hester will resign and the bank will cut 2,000 jobs.
Ahead of the opening bell, Wall Street also appeared headed for losses. Dow Jones futures fell 0.6 percent while S&P 500 futures lost 0.3 percent.
Adding to Japan's woes was the dollar's recent fall against the yen — the dollar was trading at about 94 yen on Thursday, having slipping momentarily to 93-yen levels. A rising yen spells bad news for Japanese manufacturers because it will make their exports more expensive overseas.
Juichi Wako, equity market strategist at Nomura Securities Co. in Tokyo, said the stock market drop was due to a reversal of the money flow that had flooded Japan in recent months, partly on inflated hopes for "Abenomics," as Prime Minister Shinzo Abe's fiscal and monetary policies have been dubbed.
In April, the Bank of Japan announced a massive stimulus in an attempt to encourage economic growth and get inflation up to 2 percent. The euphoria drove the Nikkei up to five-year highs but market sentiment has since fluctuated wildly and the index is now around 20 percent down from its recent peak.
Much of the overwrought excitement was calming and the money was reverting to the U.S., Wako said.
Markets are also looking at the future course of U.S. monetary policy following a solid, if unspectacular, improvement in economic data.
Investors now expect some reduction in the Federal Reserve's monthly asset purchases sometime this year. Fed stimulus has been one of the main reasons why many assets, such as global stock markets and emerging markets, have rallied in recent months.
Analysts said markets will likely remain on edge until next week's Fed policy meeting for greater clarity on the timing and extend of any tapering.
Elsewhere in Asia, the Hang Seng index fell 2.2 percent to 20,887.04, while the Kospi in South Korea lost 1.4 percent to 1,882.73.
Mainland Chinese were pummeled as accumulating signs of a slowdown in growth in the world's No. 2 economy caused investors to retreat. The Shanghai Composite Index slid 2.8 percent to 2,148.36, its lowest close in six months.
The euro dropped to $1.3310 from $1.3331 late Wednesday in New York. The dollar fell to 94.41 yen from 95.71 yen.
Benchmark crude oil was down 48 cents to $95.50 per barrel in electronic trading on the New York Mercantile Exchange.
AP Business Writers Pamela Sampson in Bangkok, Elaine Kurtenbach in Tokyo and Toby Sterling in Amsterdam contributed to this report. Researcher Fu Ting contributed from Shanghai.
Follow Kurtenbach on Twitter at www.twitter.com/ekurtenbach