* Nikkei down 1 pct, closes at lowest since April 19
* Volume sinks to second lowest this year
* Exporters hit by yen's rise, Sony down 2 pct
By Chikafumi Hodo and Ayai Tomisawa
TOKYO, April 26 (Reuters) - Japan's Nikkei average closed at a one-week low on Tuesday, losing 1.2 percent as exporters were hit by a stronger yen in thin trade ahead of corporate earnings announcements.
Falls in exporter shares undermined the overall market after the dollar hit a four-week low against the yen , reducing the value of their overseas earnings.
Electronics giants fell, with Sony Corp losing 2.1 percent to 2,415 yen and Toshiba Corp down 2.8 percent at 416 yen.
Among carmakers, Toyota Motor Corp fell 2.4 percent and Honda Motor Co lost 1.6 percent.
"Perhaps the dollar's recent weakness against the yen is the key factor, making Japanese stocks less attractive. On top of that the impact of the earthquake is putting additional pressure on prices," said Nagayasu Yamagishi, a strategist at Mitsubishi UFJ Morgan Stanley Securities.
"Volume is extremely thin ahead of Japanese and U.S. monetary policy meetings. The market simply can't move much as there are many factors -- we have to confirm the outcome of the FOMC and earnings," Yamagishi said.
Federal Reserve Chairman Ben Bernanke will hold the first ever post-meeting news conference by a Fed chief on Wednesday, and market participants will be monitoring his comments for hints on future policy tightening.
The Nikkei finished the day down 113.27 points at 9,558.69, its lowest close since April 19.
The broader Topix fell 0.8 percent to 833.64.
Market turnover struggled to pick up, with only 1.54 billion shares changing hands on the Tokyo Stock Exchange's first section, the second-lowest amount this year following Monday's 1.46 billion shares.
Analysts said support for the Nikkei is now pegged at the psychologically key 9,500 line after it fell below previous support at its 25-day moving average of 9,608.
AUTO SHARES DOWN, RETAIL INVESTORS BUY SMALL CAPS
Auto shares were also undermined after the Nikkei business daily said last month's huge production cuts will translate into roughly 1 trillion yen ($12.21 billion) in lost revenues for Toyota and other Japanese automakers, citing its own estimates.
"Carmakers are being hit by the double-whammy of the article and a stronger yen. But such drops may be priced into the market soon as investors will likely focus on their earnings," said Kenichi Hirano, a strategist at Tachibana Securities.
DeNA Co jumped 5.6 percent to 2,988 yen after it said on Monday it would tie up with NTT DoCoMo Inc to provide a direct link to its popular social gaming platform "Mobage" through DoCoMo cellphones and smartphones. DoCoMo, Japan's largest mobile phone operator, rose 0.7 percent to 144,600 yen.
"Individual investors have been stepping in to buy small cap shares, but such flows are only for investments in the short term. But otherwise, big investors and foreigners are largely on the sidelines," said a senior trader at a foreign brokerage.
The trader said retail investors were detected pouring money into DeNA and another mobile social gaming company, Gree Inc , which closed up 3.1 percent at 1,555.
After the bell, Canon Inc reported a 5 percent fall in quarterly operating profit and cut its annual outlook to below market expectations as it copes with the effects of Japan's earthquake, which has hit suppliers and hobbled production.
Separately after the close, Daiwa Securities Group , Japan's No.2 brokerage, posted a surprisingly large quarterly loss, its fourth in five quarters, hurt by valuation losses on its investments.
Daiwa, which is expanding investment banking services in Asia in a bid to make up for shrinking profits in its retail investment business at home, posted a 33.1 billion yen net loss for January-March, compared with a loss of 2.8 billion a year earlier. ($1 = 81.845 Japanese Yen) (Editing by Michael Watson)