Global Stocks

European stocks advanced on Wednesday after a choppy start to the day, as a rally for banks and advertising giant WPP PLC outweighed pressure from falling commodity prices.

The Stoxx Europe 600 index SXXP, +0.39% gained 0.4% to 344.93, closing in positive for a third straight session.

U.K. stocks closed in the red Wednesday, with resource companies leading the charge south on the back of a slide in commodity prices and a mixed earnings report from mining giant Glencore PLC.

The FTSE 100 UKX, -0.48% dropped 0.5% to finish at 6,835.78, partly erasing a 0.6% gain from Tuesday.

The S&P 500 and Dow industrials on Wednesday finished at their lowest levels since early August as selling in health-care shares, sparked by intensifying outrage over the pricing of a lifesaving drug by Mylan, put pressure on the broader market.

The slump in Mylan nudged the health-care sector lower and weighed on the exchange-traded iShares Nasdaq Biotechnology ETF IBB, -3.36% which was down 3.4%-its worst daily slide in two months, according to FactSet data.

The Nasdaq Composite Index COMP, -0.81% suffered the brunt of the market's retreat, trading down 42.38 points, or about 0.8%, to close at 5,217.69. The tech-heavy index closed at its lowest level since Aug. 8., and experienced its worst daily slump in three weeks.

Asian stocks edged higher on Thursday but clung to recent well-worn trading ranges while the greenback held firm against regional currencies ahead of a speech by Federal Reserve Chair Janet Yellen at a global central bankers' meeting.

Market expectations have increased that Yellen might indicate a clearer timeframe for the next U.S. rate hike after strong housing data this week and hawkish comments by other Fed officials, but many analysts expect her to strike a more neutral stance.

On Wednesday, futures markets were indicating just an 18 percent chance the U.S. central bank would hike rates at its policy meeting next month, and roughly 50 percent odds of a rate increase in December, according to CME Group's FedWatch tool.