Markets in Tokyo and Sydney opened sharply lower Thursday, following the lead of U.S. stocks, which tumbled precipitously in highly volatile trading.

Japan’s blue-chip Nikkei 225 average opened down 1.8 percent, putting it below the 9,000 level it regained Wednesday after the previous day’s heavy selling. The Australian Standard & Poor’s /ASX 200 index was down more than 1 percent at the opening bell, putting it on track to reverse two days of increases.

Asian markets had ended Wednesday mostly in positive territory, with the Nikkei 225 gaining 1.05 percent and the ASX 200 advancing 2.64 percent. But the rally lost speed in Europe, where escalating fears over banks’ exposure to heavily indebted Greece, Spain, Italy and Portugal drove stocks lower and helped fuel a selloff in the United States.