The US market rebound came after William Dudley, the head of the New York branch of the Federal Reserve and one of the most influential members of its monetary policy board, said the reasons for moving to a long-awaited rate hike in September had weakened.

"The slowdown in China could lead... to a slower global growth rate and less demand for the US economy," said Dudley. "We're concerned about the outlook, how is the economy going to perform in the future... And there, international developments and financial market developments do have relevance because they can impinge and affect the economic outlook."

Widespread concerns remained over whether Chinese authorities were doing enough to calm the markets and sustain economic activity at the current level, despite the injection of hundreds of billions of yuan into markets to support stocks and the currency itself.

Even another rate cut by the People's Bank of China did not ease the worries that a slowdown in the world's second-largest economy could stall world growth.

The day saw mixed movements in major bourses -- Shanghai fell another 1.27 percent and European shares, represented by the Eurostoxx 50 blue chip index, lost 1.47 percent while Tokyo added 3.2 percent.

Wall Street was assisted by a 5.7 percent gain from Apple. The S&P 500 closed with a 3.90 percent gain, the Dow added 3.95 percent, and the Nasdaq Composite was up a heady 4.24 percent.

Even with the US gains, S&P-Dow Jones Indices said $3.45 trillion in value had been wiped from shares around the world over seven days in the China-driven rout.

av/lw (AP, Reuters, AFP)