U.S., euro zone business growth slower, China contracts

LONDON/NEW YORK (Reuters) - U.S. and euro zone business growth slowed in May while China's factory sector contracted again, reinforcing the need for major central banks to continue supporting economic growth. The U.S. Federal Reserve is seen unlikely to tighten monetary policy in June since the world's biggest economy barely grew at the start of the year. Growth in euro zone business activity also weakened in May, just two months after the European Central Bank launched a 1-trillion-eu