London's FTSE index pared gains to close lower on Wednesday as investors awaited the latest monetary policy decision from the U.S. Federal Reserve.
The FTSE 100 index was 0.3% higher in early trades but ended the session 0.5% lower; other major European markets were closed for the May Day public holiday.
Chipmaker AMS held its position at the top of the European benchmark for a second consecutive day, after the Apple supplier reported an upbeat outlook for the second quarter on Tuesday. Shares of the Austrian group were 21% higher at the end of Wednesday's trading session.
Shares of U.K. supermarket Sainsbury were more than 4% higher at the closing bell, making it the best performer on the FTSE. Earlier in the day, the company released its full-year preliminary results with underlying pretax profits beating expectations.
Computer hardware maker Logitech tumbled to the bottom of the European benchmark, with shares losing 6% despite the company meeting expectations with its first-quarter earnings. Traders told Reuters the sell-off followed Logitech shares gaining 40% since the beginning of 2019, rather than the earnings report.
Shares of the LSE Group were more than 3% higher after first-quarter total income was up 5% year-on-year to £546 million ($712 million).
Global investors are mainly focused on the latest monetary policy decision by the U.S. central bank's Federal Open Market Committee (FOMC) Wednesday. The Fed will make a statement at 2 p.m. ET, following the conclusion of their two-day meeting and there will be a post-meeting news conference.
The Fed is widely expected to hold interest rates steady but investors will be looking to see if the central bank changes its dovish tone. Ahead of the meeting, President Donald Trump called for a 1% rate cut and more quantitative easing.
Markets are assigning about a 65% chance of a rate cut by the end of the year, though individual Fed members have said they see little chance of any loosening in policy ahead.
Meanwhile, Venezuela is being watched closely amid mass protests against the Venezuelan government Tuesday. These took place after opposition leader Juan Guaido called on the population to take to the streets against President Nicolas Maduro.
Guaido said Maduro no longer had the support of the military and asked supporters to take to the streets again Wednesday.
Turmoil in Venezuela prompted a rise in oil prices Tuesday with Brent crude rising above $73 a barrel. Prices had retreated by Wednesday morning, however, with international benchmark Brent crude futures trading at $71.63 per barrel and U.S. crude futures at $63.36 per barrel.
Most major Asian markets are closed for holidays Wednesday but stocks in Australia gained in morning trade.
- CNBC's Jeff Cox contributed to this report.