Measures taken by the Chinese government to stem the rout in that nation's stock market also appeared to be working.
KEEPING SCORE: The Standard & Poor's 500 index increased 23 points, or 1.2 percent, to 2,074. The Dow Jones industrial average rose 213 points, or 1.2 percent, to 17,727.77 as of 10:04 a.m. Eastern time. The Nasdaq composite gained 71 points, or 1.4 percent, to 4,909.
THE GREEK SAGA: The Greek government is set to deliver a list of reforms and austerity measures to creditors later Thursday. The country is trying to secure a bailout at meeting of the European Union's 28 leaders Sunday. Irish Finance Minister Michael Noonan put the chances of a deal at better than 50 percent while Donald Tusk, who will chair Sunday's meeting, indicated that some form of debt relief should be on the table.
EUROPE REBOUND: In Europe, Germany's DAX spiked 2.1 percent, while the CAC-40 in France rose 2.5 percent. The FTSE 100 index of leading British shares was 1.5 percent higher.
CHINA TURMOIL: In China, frantic efforts by authorities to stop the nearly monthlong slide in the country's stock markets appeared to be giving the market an artificial bounce, analysts said. A flurry of measures announced Wednesday included a government order to state companies and executives to buy shares.
A directive from the China Securities Regulatory Commission requires investors owning more than 5 percent of a company's shares to not sell any of their holdings for the next six months.
ASIA SCORECARD: The Shanghai Composite in mainland China surged 5.8 percent after initially opening sharply lower. The index is still down 27 percent in the last month. Hong Kong's Hang Seng also rebounded, climbing 3.7 percent after suffering its biggest drop since the financial crisis.
ENERGY: Benchmark U.S. crude rose $1.06 to $52.70 a barrel on the New York Mercantile Exchange. Brent crude, an international benchmark, rose $1.59 to $58.65 a barrel in London.
BONDS AND CURRENCIES: Bond prices fell, pushing up the yield on the 10-year Treasury note to 2.27 percent from 2.20 percent on Wednesday. The euro fell to $1.1053 while the dollar rose to 121.30 yen.