* Oil, gas stocks follow commodities decline
* Selling in blue-chip shares as worries weigh before earnings
* Tokyo Electric down for first time in three days
* Nikkei sinks below support at 9,612.51 -- April Nikkei options settlement
TOKYO, April 12 (Reuters) - Tokyo stocks slipped for a second straight session on Tuesday, as investors sold off blue-chip exporters including car and electronics makers, on the view that the post-quake rebound has been too rapid and they could not fully price in the impact of the disaster that struck Japan on March 11.
The Nikkei sank below a crucial support level after oil prices extended the previous day's nearly 3 percent losses, spurring profit-taking in energy shares that were seen as overbought after recent rallies.
"Many people worry that more and more large-cap companies including big automakers may cut their earnings estimates for the business year," said Hideo Arimura, senior fund manager at Mizuho Asset Management.
Sony Corp fell 2.5 percent to 2,513 yen and Toyota Motor Corp dropped 1.5 percent to 3,210 yen.
Trading volumes remained depressed as the market awaited the first post-quake Japanese earnings reports at the end of April, with market participants looking to U.S. earnings for clues about damages to global supply chains from the quake.
The Nikkei has already recouped about two-thirds of the ground lost since the March 11 earthquake, but analysts said potential gains before earnings would likely be hard won.
"The market until now thought that the quake's impact would be most severely felt in the April-June quarter, but it seems it may drag on for at least another quarter, keeping the market depressed for much longer," said Arimura.
Alcoa Inc kicked off the U.S. earnings season reporting first-quarter profit that beat estimates, but revenue of the aluminium maker missed forecasts and the stock fell 3.6 percent in post-market trade.
By midmorning the Nikkei fell 1.4 percent or 139.74 points to 9,581.30, while the broader Topix index dropped 1.2 percent to 841.85.
The benchmark index broke below a crucial support level at 9,612.51, where April Nikkei options settled last week, and investors were keen to see whether the benchmark could rise back above it before the closing bell.
OIL STOCKS SOLD
Shares of oil and gas developers Inpex Corp and Japan Petroleum Exploration Co (Japex) fell prey to aggressive profit-taking as oil extended the previous day's decline amid mounting concerns that rising fuel costs will erode demand and threaten the economic recovery.
Inpex, Japan's biggest oil and gas developer and one of the biggest post-quake outperformers -- up 15 percent since the close of March 10, the day before the quake -- fell 2.9 percent to 635,000 yen. Japex lost 2.3 percent to 4,060 yen.
Analysts said that while falling commodities prices will pressure energy stocks, in the long run they will also help to ease worries over the impact of rising raw material costs on input costs and margins, providing some support to the market.
Shares of Tokyo Electric Power Co , the operator of the stricken Fukushima Daiichi nuclear power plant, fell more than 8 percent to as low as 458 yen on Tuesday, pulling back after posting strong gains in the last two sessions.
Tokyo Electric shares came under strong selling pressure on a report in the Nikkei daily on Tuesday that the power giant would not pay a dividend for the previous financial year to March and would also forgo payouts for the current year, hit by increasing losses related to a crippled nuclear plant after last month's devastating earthquake. [ID:nL3E7FB32A] (Reporting by Antoni Slodkowski; Editing by Chris Gallagher; antoni.slodkowski@thomsonreuters.com; +81-3-6441-1875; Reuters Messaging: rm://ayai.tomisawa.reuters.com@reuters.net; If you have a query or comment on this story, send an email to news.feedback.asia@thomsonreuters.com)