Tokyo's benchmark Nikkei 225 index fluctuated wildly in morning trade Wednesday after two highly volatile days that saw global markets whipsaw.

The Nikkei added 2.81 percent, or 975.12 points, to 35,650.58, having swung from a more than two percent loss to more than a three percent gain in morning trade.

The broader Topix index added 3.86 percent, or 94.07 points, to 2,528.28.

Trade was jittery after the Nikkei surged more than 10 percent on Tuesday, a day after tanking more than 12 percent on concerns over the US economy and a stronger yen.

Wall Street stocks had a calmer session Tuesday, although analysts warned that more turbulence could be in store for global markets.

The yen strengthened to 146.89 against the dollar, from 144.68 in New York.

A higher yen is a negative for Japanese exporters, and recent rallies -- although fluctuating -- have been fuelled by central bank policy decisions that reversed months-long trends.

"The market will likely remain nervous about the direction of the dollar-yen," Monex said.

The brokerage noted that Tokyo shares had dipped in early trade after sharp rises on Tuesday and as the yen appreciates.

Major shares reversed earlier losses to mark gains. Toyota jumped 2.52 percent to 2,581.5 yen. Semiconductor test-maker Advantest rose 1.47 percent to 6,228 yen. Nintendo also rose 3.46 percent to 7,767.