By Mari Saito
TOKYO (Reuters) - Japan's Nikkei share average ended lower in choppy trade and closed out its worst April since 2005 on Friday, after the Bank of Japan's move to boost its bond buying failed to ignite lasting confidence among investors over the fragile economy.
Stocks briefly picked up and the yen weakened after the BOJ announced during the afternoon session that it would increase its asset purchases by 10 trillion yen and expand buying of exchange-traded funds and real estate-linked funds.
But strategists said market participants had mostly priced in the BOJ decision and so they quickly pocketed profits ahead of a three-day weekend. Tokyo markets are closed on Monday for a national holiday.
"Markets reacted positively to the BOJ's move to expand its balance sheet by buying more risk assets such as ETFs. But in comparison to operations by overseas central banks, Japan still lacks dynamism," said Seiki Orimi, a senior investment strategist at Mitsubishi UFJ Morgan Stanley Securities.
"It's like the bank is being publicly humiliated by the government into doing more for the economy. And they're still not going far enough," Orimi said.
The benchmark Nikkei ended down 40.94 points at 9,520.89, reversing course after jumping as high as 9,691.70 shortly after the BOJ announcement.
The broader Topix slipped 0.7 percent to 804.27.
Trading volume spiked, with 2.19 billion shares changing hands on the main board, up from 1.56 billion shares on Thursday.
With the initial euphoria over the BOJ quickly fading, investors are turning their focus to domestic corporate earnings and Europe.
Highlighting some of the challenges facing Japan's blue chips this earnings season, Nintendo skidded 5.6 percent after it posted its first ever annual operating loss on Thursday, citing shrinking sales of its ageing Wii gaming console and weak demand for its new 3DS handheld device.
After the closing bell, Sharp Corp reported a record net loss of 376.1 billion yen for the just-ended fiscal year, hammered by weak sales of LCD panels and TVs. The stock gained 1.2 percent ahead of the results.
Still, the Topix's one-month earnings momentum - analysts' earnings upgrades minus downgrades as a percentage of total estimates - improved further to 5.4 percent in April from 3.6 percent last month, data from Thomson Reuters I/B/E/S showed.
Nearly two-thirds of the 27 Nikkei companies that reported January-March earnings before Friday beat or met market expectations, data from Thomson Reuters StarMine showed, much better than the previous quarter.
Bucking the market, Softbank Corp surged 3.1 percent after it hiked its dividend to 40 yen from 5 yen after posting an operating profit of 675.3 billion yen for the year to March.
"It was certainly impressive that the BOJ decided to buy more ETFs and REITs, which was a slight surprise. But once that's out, we're all looking to tonight's Italian debt auction and GDP figures from the United States," said Kenichi Hirano, operating officer at Tachibana Securities.
Concerns over peripheral economies were sparked once again after Standard & Poor's cut Spain's credit rating by two notches and said the country's outlook could deteriorate even further unless ambitious measures were taken at the European level.
The Nikkei shed 5.6 percent this month, marking its worst April performance in seven years on the back of a global equities correction driven by mixed economic data out of the United States, slower growth in China and resurgence of European sovereign debt worries.
(Additional reporting by Dominic Lau and Sophie Knight; Editing by Chris Gallagher)