With an expected Federal Reserve interest rate cut already priced in, having fuelled a healthy rally, and few other catalysts to drive buying, analysts said investors are also cashing out.
The losses in Asia followed a negative lead from Wall Street, where big-name firms including Caterpillar and United Technology sank on weak corporate reports.
"Stocks' strong gains are finally succumbing to profit-taking," Alec Young at FTSE Russell told Bloomberg News.
"Earnings and guidance so far have been mixed and, given the big run-up, it's no surprise there's little investor tolerance for even a hint of disappointment."
In early trade Hong Kong and Shanghai were each down 0.7 percent while Tokyo ended the morning 1.6 percent lower, hit by a stronger yen and data showing another drop in exports as Japan feels the impact of falling demand and global trade uncertainty.
Sydney and Singapore both lost 0.3 percent, Seoul fell 0.5 percent and Taipei was off 0.1 percent. However, Wellington and Manila eked out small gains.
Energy firms across Asia tracked their US counterparts following another steep drop in oil prices that came after government data showing a pick-up in US gasoline inventories.
The figures represent the weakest demand in five years, analysts said.
"Gasoline consumption is painfully weak given US consumers are in peak driving season, which will be invariably seen as the Grim Reaper of sorts," said Stephen Innes at Vanguard Markets.
"If we put this data set in the context of slowing China second-quarter GDP, where consumption was the most significant drag, the numbers do suggest that the global economic slowdown is being echoed through weaker global demand data. Definitely a bearish signal for oil demand."
The dollar fell against its main peers and most high-yielding currencies, having enjoyed a recent rally, on concerns about the length and depth of expected Fed rate cuts.
Adding to dollar selling were comments from the International Monetary Fund that the US unit is overvalued by up to 12 percent based on current economic fundamentals.
However, Innes questioned whether the pound could maintain its gains owing to investors' increasing concerns about the possibility Britain will crash out of the European Union in October without any agreement.