Japan's Nikkei average broke a seven-session losing streak on Thursday, boosted by big programme buying by hedge funds, which pushed the index to above 9,500, triggering short covering and accelerating the move higher, market participants said.
The Nikkei closed 0.7% higher at 9,524.79 to end its worst losing run since July 2009, after trading in and out of positive territory throughout the morning session.
"This is a futures led gain. There's been a steady amount of futures orders after the midday break and a little after 2 pm we broke above the 9,500-mark that we've been trading below and then buying accelerated to cover ahead of the options settlement tomorrow," said Masayuki Doshida, senior market analyst at Rakuten Securities.
Among the heaviest traded stocks on the main board was Sony Corp, which rose 0.9% ahead of Chief Executive Kazuo Hirai's announcement of a revival strategy after the market close.
Sony said after the bell that it is to cut about 10,000 jobs, or 6% of its global workforce, as Hirai moves to reduce costs and staunch huge losses at the electronics company.
Industry peer Sharp Corp was up 2.7% while Panasonic Corp climbed 2.1%.
Hiroyuki Fukunaga, chief executive of Investrust, said the upswing marked an end of the correction period for the Nikkei, which has lost 5.5% in April after a rally of more than 19% in the first quarter.
"I think the option special quotation (SQ) on Friday will encourage investors to adjust their positions and act as a positive catalyst for the market to fire up again. I think today was also a turning point," he said.
A slew of stock options expire on option SQ days in Japan, typically causing a spike in opening volumes.
The broader Topix gained 0.5% to 809.88.
Nearly 1.82 billion shares changed hands on the main board, down from Wednesday's 2.08 billion and last week's average of 1.96 billion.
In the morning session, stocks were steady with the market hesitant in anticipation of North Korea's long-range rocket launch, which Japan's Kyodo news agency said was unlikely to be launched on Thursday because of the weather.
"The market was waiting for the missile announcement in the morning so hardly moved at all. If it is launched and lands without incident the market should start moving again," said Fukunaga.
Defiant North Korea ignored international protests and prepared to launch the rocket which it says will be sent up some time within a five-day window beginning on Thursday.
Outperforming the index was Hitachi Construction Machinery Co Ltd, up 4.1% after the Nikkei said the company was expected to post an operating profit of 80 billion yen for the year ending March 2013, beating the company's forecast of 60 billion yen for the year ended March 2012.
Fujitsu Ltd rose 2% after the company said it was confident of doubling sales in China to 220 billion yen by 2014 due to an expansion of the IT sector in the world's second-largest economy.