U.S. STOCKS, BONDS

Stocks continued their slide after a full slate of uninspiring corporate earnings reports provided little to compel investors to step in and buy shares.

The Dow Jones Industrial Average fell 81.45 points, or 0.6%, to 14537.14. The Standard & Poor's 500-stock index slid 10.4 points, or 0.7%, to 1541.61, its lowest close in six weeks.

The Nasdaq Composite Index sank 38.31 points, or 1.2%, to 3166.36. Stocks have seen big swings this week, alternating between gains and losses, starting with Monday's 266-point decline, the Dow's biggest of the year. Tuesday's rebound was nearly washed away by Wednesday's 138-point drop for the blue chips.

In another sign of flagging momentum, the S&P 500 broke through its 50-day moving average around 1543--a threshold watched closely by traders as a short-term pivot point--for the first time this year.

Quarterly earnings reports from a host of major corporations set the tone of trading. First-quarter earnings growth for 82 of the S&P 500's companies had declined 0.4% through Thursday morning, according to FactSet, on pace to mark the second year-over-year decline in earnings in the past three quarters.

Meanwhile, corporate revenue is expected to rise 3.2% in the first quarter, well below growth of 6% in the first quarter last year, according to S&P Capital IQ.

Technology, consumer-discretionary and health-care stocks each slumped more than 1%. The financial sector also was weak after Morgan Stanley, which fell 5.4%, reported disappointing bond-trading results and sales that missed consensus forecasts.

UnitedHealth Group slumped 3.8%. The insurer's first-quarter earnings edged ahead of Wall Street's expectations, but revenue was lower than expected.

The company also lowered its full-year revenue estimate by up to $2 billion. Telecommunications stocks were a bright spot after Dow component Verizon Communications, which added 2.8%, posted first-quarter earnings that topped analyst estimates, though revenue came in shy of analyst estimates.

On the data front, U.S. workers applying for jobless benefits rose for the fourth time in five weeks, the Labor Department said. Initial jobless claims, an indication of layoffs, increased by 4,000 to a seasonally adjusted 352,000 in the most recent week, slightly more than forecast.

Business conditions for mid-Atlantic manufacturers remain barely positive this month, as the Federal Reserve Bank of Philadelphia's index of general business activity slowed in April from March. Separately, an index of leading economic indicators posted an unexpected fall in March, as consumers turned gloomy on the economic outlook.

Apple continued its slide, down 2.7%, closing under $400 a share for the first time since 2011. EBay dropped 5.9% after a downbeat current-quarter earnings outlook overshadowed first-quarter earnings that beat expectations.

American Express edged up 1.4% after its first-quarter revenue rose less than expected, offsetting earnings that were slightly above forecasts. PepsiCo gained 3% after exceeding earnings estimates.

EUROPEAN STOCKS, BONDS

European stock markets gave up early gains, closing flat Thursday as mixed corporate earnings and continued worry over global economic growth weighed on sentiment.

Traders had hoped for a strong rebound following four consecutive days of declines, but markets turned sour. Uninspiring earnings reports from U.S. blue-chip stocks Morgan Stanley, UnitedHealth Group and EBay added to the gloomy picture.

The benchmark Stoxx 600 index closed flat at 283.73. The U.K.'s FTSE 100 and France's CAC-40 also ended essentially flat at 6243.67 and 3599.36, respectively. Germany's DAX fell 0.4% to 7473.73.

Earnings news from Europe was lackluster too. Nokia shares slumped 8.3%. The Finnish company reported healthy demand for its Lumia smartphone, but reported a narrow first quarter loss.

The company's forecasts for the second quarter disappointed many analysts. Akzo Nobel fell 3.3% as the Dutch paints and chemicals company reported a decline in sales and operating profit in the first quarter.

The company added it doesn't expect an early improvement. Shares in Carrefour ended 1.1% lower after the French retailer posted a drop in sales.

Nestle gained 1.1% despite weaker-than-expected first-quarter sales. GlaxoSmithKline rose 3.2% in London, after the U.S. Food and Drug Administration late Wednesday backed the approval of the firm's Breo Ellipta drug for treating chronic obstructive pulmonary disease.

Barclays fell 2.3%. The bank said two of its top executives will depart. Utility firm RWE dropped 2.5% in Frankfurt, after confirming that earnings will come under severe pressure over the next few years as low power prices across Europe erode profitability.

ASIA-PACIFIC STOCKS, BONDS

Asian markets were mostly lower Thursday, as the rout in commodities continued, and regional companies connected to Apple followed the technology giant down.

Asian companies that supply components to, or are affiliated with Apple, were sold. LG Display dropped 4.8% in Seoul, Murata Manufacturing lost 2.9% in Osaka, and AAC Technologies Holdings fell 3.4% in Hong Kong.

Commodities were in focus once again, as copper and crude-oil prices fell sharply as investors dumped assets across the commodity complex due to broad-based risk aversion and lingering concerns over growth in China.

The resources sector was under pressure across the region. Oil company Inpex Corp. lost 2.5% in Tokyo, steel producer POSCO fell 1.4%.

in Seoul, and offshore oil producer Cnooc lost 0.3% in Hong Kong. Japan's Nikkei Stock Average fell 1.2% to 13220.07 and South Korea's Kospi Composite lost 1.2% to 1900.06.

Markets in China made only modest moves, with Hong Kong's Hang Seng Index ending down 0.3% at 21512.52 and the Shanghai Composite Index ending up 0.2% at 2197.60 in the mainland.

ANA Holdings bucked the downward trend in Tokyo, rising 3.6% following a Nikkei report saying U.S. regulators plan to lift a ban on Boeing's 787 passenger jet flights as early as this month. Battery maker GS Yuasa Corp., the batteries of which were involved in the investigation into the plane's problems, shot up 5.5%.

COMMODITIES

Base metals on the London Metal Exchange closed mostly higher on the day, rebounding from an overnight slump that had pushed copper prices to a fresh 18-month low.

However, the recovery remains fragile, analysts said. At the close of open-outcry trading, LME three-month copper was up 0.1% on Wednesday's close at $7,085 a metric ton.

Crude-oil futures prices settled higher Thursday amid bargain-hunting after a recent steep selloff, with North Sea Brent posting its first gain after six down days. News of lower exports of Nigerian crude oil buoyed prices of the European benchmark.

June North Sea Brent crude oil futures on the InterContinental Exchange settled 1.5%, or $1.44, higher at $99.13 a barrel. May-delivery light, sweet crude oil futures on the New York Mercantile Exchange settled 1.2%, or $1.01 higher, at $88.20 a barrel, after settling Wednesday at a four-month low.

Gold prices gained on more signs of an uptick in physical buying of the precious metal after its plunge early this week. The most actively traded contract, for June delivery, rose $9.80, or 0.7%, to settle at $1,392.50 a troy ounce on the Comex division of the New York Mercantile Exchange.