Asia stocks cautious before Fed, oil on defensive

TOKYO (Reuters) - Investor caution ahead of the Federal Reserve's interest rate meeting capped Asian stocks on Tuesday, while crude oil prices retreated as global growth worries overshadowed supply concerns stemming from recent Middle East tensions.The Shanghai Composite Index lost 0.25%, Hong Kong's Hang Seng rose 0.15% and Japan's Nikkei dipped 0.3%.MSCI's broadest index of Asia-Pacific shares outside Japan edged up 0.2%.Bucking the trend were Australian stocks , which rose 0.3% after..