(Reuters) -- Asian shares fell Wednesday after four days of gains, as expectations of stimulus action this week by the U.S. Federal Reserve and the European Central Bank fade, and following signs of deepening Asian economic stress.
Chinese official and non-official manufacturing data are due between 0100 and 0230 GMT, with any weakness likely to stoke fears the world's second-largest economy is losing momentum and undermine the market's fragile sentiment.
Major Asian exporters Japan, South Korea and Taiwan all reported worsening economic stress Tuesday, with Japan's manufacturing index shrinking at its fastest pace since the 2011 earthquake, due to slowing demand in Europe and China.
MSCI's broadest index of Asia-Pacific shares outside Japan <.MIAPJ0000PUS> eased 0.2 percent on Wednesday, after hitting its highest level since May 11 on Tuesday and ending July with a 3.6 percent gain, slightly ahead of June's 3.5 percent rise.
Japan's Nikkei stock average <.N225> opened down 0.8 percent. .T
Few analysts now expect the Fed to actually launch more easing at the end of its two-day meeting later on Wednesday, but it is expected to reinforce a commitment to an accommodative stance and could drop hints about more measures in coming weeks.
Pressures for an imminent Fed action have eased as Tuesday's reports beat expectations in regional manufacturing in the U.S. Midwest, home prices, and consumer confidence, coming ahead of a key nonfarm payrolls and two larger national manufacturing data.
"We are looking for, at most, a chance in the Fed's language that extends low rates through at least early-2015, which won't be the stimulus bump market participants have been hoping for," said Christopher Vecchio, currency analyst at DailyFX.
"Nonetheless, investors are largely mixed on what they feel the Fed will do going forward," Vecchio said.
The situation in Europe was far more unsettling, with no apparent consensus emerging on contentious issues, while analysts and traders see any action from the ECB may only give a temporary relief for strained bond markets in the euro zone.
The euro eased 0.1 percent to $1.2295, off Tuesday's high around $1.2330 and below a three-week high of $1.2390 touched on Friday. It has stayed above a two-year low around $1.2042 reached last week. The euro steadied at 96.04 against the yen.
The Australian dollar fell 0.2 percent to $1.0481, retreating from Tuesday's four-month high of $1.0539.
"Even if the ECB manages to deliver a policy response which genuinely stabilises peripheral bond yields, the EUR is likely to remain soggy for some time on a weak European growth profile and ongoing bank deleveraging," ANZ said in a research note.
The ECB meets on Thursday.
European shares suffered their biggest intraday fall in more than a week on Tuesday, hit by weak bank results and fresh doubts over whether the ECB could agree on concrete measures to tackle Europe's sovereign debt crisis.
Germany's finance ministry reiterated its view on Tuesday that there is no need to grant a banking licence to the euro zone's new bailout fund, a move that could let it buy virtually unlimited amounts of debt issued by troubled euro zone states.
Yields on Spanish and Italian 10-year bonds inched higher on Tuesday on growing wariness over a potential policy move, but stayed below critically high levels.
Euro zone's fiscal woes have hit the region's economy hard, with the latest report from the European Union showing that joblessness in the euro zone hit its highest level in June since the single currency was born.
Reflecting how investors shied away from riskier assets, data on Tuesday showed EPFR Global-tracked Bond Funds took in $223.2 billion while Equity Funds surrendered $31.4 billion so far this year to the week ending July 25.
Asian credit markets weakened slightly with the spread on the iTraxx Asia ex-Japan investment-grade index widening by 1 basis point after falling to its lowest since early April on Tuesday.
(Additional reporting by Ian Chua in Sydney; Editing by Michael Perry)