Chinese stocks fell and the Australian dollar skidded on Wednesday after Moody's downgraded its sovereign credit rating on China, adding to worries about the global impact of slowing growth and rising debt in Asia's economic powerhouse.Shares elsewhere in Asia also slipped, with MSCI's broadest index of Asia-Pacific shares outside Japan down 0.3 percent, despite modest gains on Wall Street overnight.Financial spreadbetter CMC Markets expected Britain's FTSE 100 to open slightly higher, Germany's DAX to start the day little changed, and France's CAC 40 to edge lower.Japan's Nikkei stock index managed to end 0.7 percent higher."At the end of the day, overseas investors had been taking a cautious stance toward China, even before this, so it was not entirely surprising to the street," said Kyoya Okazawa, head of global markets, Japan at BNP Paribas Securities in Tokyo.