Wall Street shares steadied Wednesday as investors awaited new signals on interest rates but Chinese stocks tumbled on continued disappointment over a lack of fresh stimulus in the world's second-biggest economy.
Europe's main stock markets were slightly higher.
Oil prices fell for a second day on news reports of rising US inventories and as Israel appears to be holding off -- at least for the moment -- from striking Iranian energy installations.
Wall Street rallied Monday before giving up most of those gains Tuesday and the "market looks a bit flummoxed about what the next turn will be", said Patrick O'Hare, an analyst at Briefing.com.
Last week's strong jobs report has convinced most investors that the US Federal Reserve will go slow with future interest rate cuts, but new clues should emerge this week.
Minutes from the Fed's September meeting, due later on Wednesday, will be examined for insight into the Fed's thinking.
On Thursday, a consumer prices report will show whether the central bank has brought inflation under control.
US shares were also rattled by the US Department of Justice's announcement Tuesday that it would demand that Google make profound changes to how it does business and may even consider the possibility of a breakup.
Google's parent company Alphabet was down about one percent in early trading Wednesday.
Boeing was down almost three percent after it suspended negotiations with its striking workers late Tuesday over what it said were unreasonable demands.
Chinese shares have also been volatile recently, with investors first enthusiastic about a series of steps to kickstart domestic growth and then left deflated Tuesday when a press conference did not provide any further measures.
"When the market's expectations were set sky-high for a 2-3 trillion yuan stimulus package and instead got hit with a big, fat zero, the party was over before it even began," said Stephen Innes, a partner at SPI Asset Management.
Investors are now awaiting a Saturday briefing on fiscal policy by Finance Minister Lan Fo'an for more indications about official plans.
But analysts warned there was unlikely to be the big "bazooka" stimulus akin to the support seen during the global financial crisis.
Shehzad Qazi at China Beige Book said Beijing was "opting for targeting stimulus -- including allocating funds for projects previously announced".
Hong Kong's stock market had soared more than 20 percent between the first batch of announced measures in late September and the start of this week.
The Hang Seng Index collapsed more than nine percent on Tuesday -- its worst day since 2008 -- and shed another one percent Wednesday.
Shanghai ended 6.6-percent lower on Wednesday.
The dollar climbed against its main rivals on expectations that interest rate differentials will continue to favour the US currency.
Key figures around 1245 GMT
New York - Dow: FLAT at 42,073.23 points
New York - S&P 500: DOWN 0.1 percent at 5,746.10
New York - Nasdaq Composite: DOWN 0.2 percent at 18,138.52
London - FTSE 100: UP 0.2 percent at 8,207.34
Paris - CAC 40: UP 0.2 percent at 7,533.12
Frankfurt - DAX: UP 0.3 percent at 19,122.59
Shanghai - Composite: DOWN 6.6 percent at 3,258.86 (close)
Hong Kong - Hang Seng Index: DOWN 1.4 percent at 20,637.24 (close)
Tokyo - Nikkei 225: UP 0.9 percent at 39,277.96 (close)
West Texas Intermediate: DOWN 1.2 percent at $72.72 per barrel
Brent North Sea Crude: DOWN 1.1 percent at $76.30 per barrel
Euro/dollar: DOWN at $1.0955 from $1.0981 on Tuesday
Pound/dollar: DOWN at $1.3072 from $1.3100
Dollar/yen: UP at 149.07 yen from 148.29 yen
Euro/pound: UNCHANGED at 83.80 pence