European markets opened lower on Wednesday as market participants await the US Federal Reserve's monetary policy announcement due later in the day.

The Stoxx Europe 600 index opens 0.3% lower to 298.63

Britain's FTSE 100 fell 0.1% in early deals

Spain's IBEX 35 and Italy's FTSE MIB were down 0.2% in opening trade.

Germany's DAX and France's CAC 40 were down 0.4% in opening trade

The Fed will release its post-meeting statement at 1800 GMT (2 pm ET). There will be no news briefing by Chairman Ben Bernanke. The US central bank could provide more clarity on the future pace of US monetary stimulus at the end of a two-day meet, on Wednesday.

Market participants will also be tracking eurozone-wide unemployment data and preliminary inflation data coming in from the Eurozone's statistics office.

Germany and Norway will put out unemployment data while France releases consumer spending data.

In company news, drinks maker Diageo said on Wednesday its net sales rose 5% in the year ended June, slightly above forecasts but below the company's medium term target of 6%.

French banking group BNP Paribas on Wednesday reported a 4.7% drop in second quarter net profit to €1.76bn (£1.53 , $2.33bn).

French defense firm EADS and utility Schneider Electric have released results.

British homebuilder Taylor Wimpey, French automaker Peugeot, utility company Suez Environment, Italian insurer Assicurazioni Generali and energy firm Eni will all put out earnings statements during the day

In Asia and the US

In Asia, the Japanese Nikkei finished 1.45% lower on Wednesday while South Korea's Kospi closed 0.16% lower. Australia's S&P/ASX index closed 0.46% higher.

Earlier in Asia, markets were mixed as market participants traded with caution, ahead of the Fed decsion.

"Traders globally seem to be in a wait-and-see mode before the outcome of the Fed's meeting on the timing of quantitative easing tapering," Reuters quoted Mitsushige Akino, chief fund manager at Ichiyoshi Asset Management in Tokyo.

In China, property and construction-related stocks gained on news that the Communist Party's politburo has vowed to keep economic growth steady in the second half of 2013, despite what it said were "extremely complicated domestic and international conditions."

Tuesday's Xinhua news report, which carried the statement, did not state the growth level that the politburo would defend.

Bank of America Merill Lynch wrote in a report that the politburo's message "could be interpreted that the new leadership has no intention to take further measures to restrict home demand and tighten financing of the property sector."

On Wall Street, the Dow and the S&P 500 closed flat on Tuesday as investors exercised caution ahead of the Fed policy statement. However, the Nasdaq logged a new 12-year high, boosted by tech stocks.

The Dow finished 1.38 points lower at 15,520.59, while the S&P 500 closed 0.63 higher at 1,685.96.

The Nasdaq ended 17.33 points higher at 3,616.47, logging its highest close in nearly 12 years.