The dollar edged toward a 15-year low against the yen on Wednesday after the Federal Reserve moved to bolster the weakening U.S. economy, while technology plays dragged Asian stocks lower.
The fall in regional shares was largely contained, however, as the Fed's move to buy more U.S. government bonds had been expected after a string of weak economic reports in recent months raised fears it could slide back into recession.
Traders also drew some comfort from fresh data from China, which confirmed its economic growth was moderating but showed no signs it was in danger of a hard landing.
The U.S. central bank said on Tuesday it would reinvest the money from maturing mortgage bonds it holds into government debt to counter recent signs of economic weakness. It left interest rates near zero and renewed its pledge to keep them low for an extended period.
The step marked an important policy shift for the Fed, which only a few months ago debated how to start rolling back some of its emergency stimulus schemes put in place during the global financial crisis.
The move, along with the Fed's more somber assessment of the economy, added more pressure on the ailing U.S. dollar, which continued to weaken against the yen.
Worries about a further strengthening in the yen against the dollar grew after the Fed's new steps toward easing policy and with the Bank of Japan maintaining the status quo, said Masaru Hamasaki, a senior strategist at Toyota Asset Management.
Japan's Nikkei average <.N225> dropped more than 2 percent, as yen strength undermined exporters, with shares in Honda Motor Co <7267.T> falling 2.8 percent, Canon Inc <7751.T> shedding 2.3 percent and Sony Corp <6758.T> falling 2.1 percent.
The MSCI index of Asia Pacific stocks outside Japan fell 1.2 percent, dragged down by tech counters on worries that corporate and consumer demand could slow.
Korean shares fell 0.7 percent as Hynix Semiconductor <000660.KS>, the world's No.2 memory chip producer, dropped nearly 4.9 percent following tumbles in U.S. chipmakers on concerns of weak PC sales growth given the faltering recovery in the United States.
Overnight, the Dow Jones industrial average <.DJI> and the Standard & Poor's 500 Index <.SPX> fell but closed off their lows after the Fed pledged to underpin the recovery. <.N>
But tech companies pressured the Nasdaq, with chipmakers Intel Corp
The dollar dipped a fifth of a percent to 85.32 yen, edging toward an eight-month low of 85.02 yen hit last week. If it slips below November's low of 84.82 yen, it would mark the currency's weakest level in 15 years.
The dollar could fall below 85.00 yen at any moment, says Shuichi Kanehira, head of FX spot trading at Mizuho Corporate Bank.
The Australian dollar shed 0.8 percent against the yen to 77.44 yen, the euro slid 0.7 percent to 111.85 yen, and sterling fell 0.6 percent to 134.72 yen.
The low-yielding yen is a funding currency for carry trades and tends to rise in times of market stress.
U.S. Treasuries prices rallied, with yields on the benchmark 10-year U.S. Treasury note falling to 2.7523 percent, the lowest since early March.
Elsewhere, oil fell 19 cents to $80.06 a barrel on demand concerns after data showing a rise in U.S. crude imports overshadowed a deeper-than-expected decline in crude stocks.
Spot gold gained 35 cents to $1,202.20 an ounce after the Fed's move, still below a 3-week high of $1,212.61 hit last week.
(Additional reporting by Aiko Hayashi, Masayuki Kitano and Rika Otsuka in TOKYO; Editing by Kim Coghill)