The Stoxx Europe 600 index opened 0.2% lower to 320.17.
Britain's FTSE 100 index opened 0.3% lower.
France's CAC 40 opened 0.4% lower.
Germany's DAX 30 opened 0.2% lower.
Spain's IBEX 35 was trading 0.10% lower after opening lower.
Italy's FTSE MIB was trading 0.02% higher after opening lower
The US Federal Reserve, unsure if America's economy can sustain itself in the absence of external stimulus, decided to extend its massive monthly bond-buying programme.
The Fed's latest policy outlook was believed to be less dovish than investors had expected.
On 30 October, the world's most powerful central bank said it would continue buying securities worth $85bn (£53bn, €62bn) a month, and cited weak growth in the world's largest economy as the reason behind its decision.
Wednesday's decision marks the second time that the Fed has deferred the planned reduction of its bond-buying programme.
Without openly referring to the recent partial government shutdown, the Fed criticised government policies, saying "fiscal policy is restraining economic growth".
The policy-setting committee said that economic activity expanded at a moderate pace, and added that unemployment remained at elevated levels despite some improvement in the job market.
Meanwhile, the recovery in the housing sector has slowed down recently, although household spending has improved. The committee also highlighted the fact that inflation had been running below its long-term objective.
"The [FOMC] committee decided to await more evidence that [economic] progress will be sustained before adjusting the pace of its purchases," the Fed said in a statement.
"Accordingly, the committee decided to continue purchasing additional agency mortgage-backed securities at a pace of $40bn per month and longer-term Treasury securities at a pace of $45bn per month."
Paul Ashworth, Chief US Economist at Capital Economics said in a note to clients: "The Fed's decision to maintain its asset purchases at $85bn per month will, given that most commentators expected a modest reduction in the pace today, be immediately bond and equity positive. We wonder, however, whether the longer lasting reaction will be increased volatility in markets, as the Fed's communications become even more confused".
In the accompanying statement, the Fed acknowledges that there has been "growing underlying strength in the broader economy", but wants to "await more evidence that progress will be sustained before adjusting the pace of its purchases." Clearly the Fed has been spooked by the extent of the surge in long-term interest rates over the past couple of months and the impact that now appears to be having on the housing market, Ashworth said.
"We suspect officials are also increasingly concerned, as we are, that Congress could trigger a Federal shutdown within the next month. Looking at the Fed new forecasts, the median projection from all meeting participants puts the fed funds rate at 1.0% at end-2015 and 2.0% at end-2016. That is slightly more dovish than the futures market had priced in before the announcement. Fed funds futures had the rate at 1.15% at end-2015 and 2.0% by August 2016 (the contracts don't go as far as December 2016 yet.)," Ashworth added.
"Our suspicion now is that the Fed will wait until the December FOMC meeting before seriously considering again whether to begin tapering or not, which is the next time the forecasts will be updated and a press conference is scheduled", he added.
In company news, British Telecom said that more than two million homes had subscribed to its new sports service, boosting BT's quarterly consumer revenue growth-rate to its highest in a decade.
The demand for broadband and its new sports service pushed up consumer revenue by 4% in the second quarter, its best performance in 10 years, the company said in a statement on 31 October.
France's top bank BNP Paribas reported a 2.4% increase in third-quarter net income.
Novo Nordisk, the world's largest insulin maker, said its third-quarter profit rose 13%.
British oil and gas firm Shell, Anglo-American miner Glencore Xstrata and rival Antofagasta will release their earnings updates during the day.
British pharmaceutical company AstraZeneca, Germany airline Lufthansa and pharma firm Bayer will also put out its earnings updates.
In Asia and the US
In Asia, the Japanese Nikkei finished 1.20% lower, South Korea's Kospi closed 1.43% lower, and Australia's S&P/ASX finished 0.10% lower.
Earlier, markets outside India traded lower, and followed a downbeat handover from Wall Street, after the Fed decision.
However, The Bank of Japan's decision to leave its monetary stimulus program unchanged provided a little respite to the markets.
On Wall Street, indices ended lower on 30 October, as investors took profits after the Fed decision.
The Dow finished 61.59 points lower at 15,618.76.
The S&P 500 ended 8.64 points lower at 1,763.31 while the Nasdaq closed 21.72 points lower at 3,930.62.
"We've been up so many days in a row, you set a record every day, it's not surprising people decided to take some profits," JJ Kinahan, chief strategist at TD Ameritrade in Chicago told CNBC.
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