The Stoxx Europe 600 edged down 0.2% in the early minutes of trading, weighed by a 1.1% drop in the basic resources sector. Mining shares were among the worst performers as Chinese iron-ore futures fell sharply after a winning streak and copper futures shed 0.9% to $5,754 a ton.
Futures pointed to 0.2% opening losses for the S&P 500 and Dow Jones Industrial Average after shares of index heavyweight Apple Inc. fell in after-hours trading on Tuesday. The world's most valuable company posted its first quarterly increase in profit in more than a year but reported tepid iPhone demand, weighing on share prices.
Many investors were also waiting for the latest release from the Federal Reserve, due later Wednesday. Investors currently price a less than 5% chance of a rate rise in May, according to CME Group, but they will be watching the bank's update on recent economic developments following a modest pullback in recent data releases, and for any hints at a rate increase in June. The U.S. central bank will parse two more employment reports, including one on Friday, ahead of that decision.
Market participants will also be looking for any updates on the Fed's balance sheet. Minutes from the Fed's March meeting showed some agreement that shrinking the central bank's $4.5 trillion portfolio of Treasury and mortgage securities could start by year's end.
10-year U.S. Treasury yields edged down a touch to 2.290% from 2.296% Tuesday ahead of the Fed meeting, while the WSJ Dollar Index, which tracks the dollar against a basket of 16 currencies, was up 0.1%.
French 10-year yields edged lower to 0.740% from 0.745% while German yields fell to 0.315% from 0.325% ahead of a televised debate later Wednesday between Emmanuel Macron and Marine Le Pen, who face off in Sunday's final round of the French presidential election. Yields move inversely to prices.
Elsewhere, bank stocks dragged down Australian bourses for a second session following an underwhelming report from Australia and New Zealand Banking to start that sector's earnings season, with the S&P ASX 200 off 1%.
Weakness among the lenders and declines in shares of mining companies offset a partial rebound in some oil-related stocks in Australia as crude prices bounced in Asia on Wednesday. Brent crude oil was last up 0.9% at $50.91 a barrel.
Chinese equities were mostly weaker as investors sold stocks related to the Xiongan economic zone, a proposed megacity a two-hour drive south of Beijing. The Shanghai Composite Index was down 0.3%.
Markets in Japan, South Korea and Hong Kong were closed for holidays.