By Chao Deng 

Stocks across Asia fell Wednesday with heightened expectations that the U.S. is headed for a rise in interest rates after comments from a Federal Reserve board member.

The Shanghai Composite Index opened 0.3% lower at 3745.65 and the smaller Shenzhen Composite fell 0.1% to 2148.78.

Despite gaining 3.7% Tuesday, after Chinese authorities late Monday moved to clamp down on short selling, the Shanghai index is still off more than a quarter from its June high. The new short-selling rules require investors to wait at least one day to cover their positions and pay back loans used to buy shares. When shorting a stock, investors sell borrowed shares on the belief they can buy them back at a lower price later, pocketing the difference.

Australia's S&P ASX 200 was down 0.7%, Japan's Nikkei Stock Average was down 0.2% and South Korea's Kospi lost 0.1%, following U.S. stocks' slide Tuesday after Federal Reserve Bank of Atlanta President Dennis Lockhart said the economy is ripe for a rise in short-term interest rates. The Fed's easy-money policies after the global financial crisis, broadly mirrored by global central banks, have helped fuel stock rallies.

"Investors are looking for clues to the U.S. central bank's rate hike timing," said Shun Otsuka, general manager of research and strategy at Ichiyoshi Asset Management, adding that markets will be watching monthly jobs data, set for release on Friday. Investors have been parsing economic data, from inflation to wages, for clues about when the Fed might raise rates.

Midway through Japan's earnings season, investors also are monitoring which companies might announce share buybacks to increase the appeal of shareholder returns, added Mr. Otsuka. He noted that the scale of buybacks in terms of share value is already at a seven-year high.

Late Tuesday in Washington, officials at the International Monetary Fund said China will likely have to move ahead with market liberalization before it labels the country's yuan a reserve currency, signaling a decision could be pushed into next year.

The U.S. dollar traded as high as 6.2220 against the Chinese yuan, from 6.2180 late Tuesday in Asia. The closely managed yuan has been stable in recent months, despite volatility in China's stock market, but markets expect it to weaken.

The Australian dollar, which had fallen near six-year lows earlier this week, strengthened after the central bank kept interest rates steady Tuesday and unexpectedly dropped its usual rhetoric about the need for further currency depreciation. The currency last traded at $0.7372, giving up gains after trading as high as $0.7428 yesterday.

"The market was completely caught off guard because, given the weakness in the Chinese economy and the decline in commodity prices, everyone thought that not only would Australian data be weak but the Reserve Bank would grow increasingly dovish," said Kathy Lien, managing director at BK Asset Management in New York.

Oil prices rose in U.S. trading overnight on expectations inventory data due Wednesday would show U.S. crude-oil supplies fell last week, although prices remain near multi-month lows. In Asia trade, futures for Brent crude were up 0.2% at $50.09.

Gold is down 0.6% to $1,084.20 in Asian trade.

Bradford Frischkorn and Vera Sprothen contributed to this article.

Write to Chao Deng at Chao.Deng@wsj.com