Nikkei ends up 0.6 pct after rollercoaster ride

TOKYO (Reuters) - Japan's Nikkei average ended up 0.6 percent on Tuesday after a rollercoaster day that saw it climb more than 510 points from low to high, with bank shares such as Mizuho Financial Group sitting in the front seats.

A spate of short-covering took both the Nikkei and the broader TOPIX index into positive territory in a matter of minutes on news that Citigroup had reached a deal to sell a $7.5 billion stake in itself to the Abu Dhabi Investment Authority.

The Nikkei ended up at 15,222.85, a gain of 87.64 points. The broader TOPIX was up 0.8 percent at 1,478.78.