* Nikkei to fall further as quake impact is priced in -fund manager
* Yen fall impact limited as production problems weigh -fund manager
* TEPCO tumbles to new low on debt worries
* Resource-related stocks fall on profit-taking after rallies
By Antoni Slodkowski
TOKYO, April 6 (Reuters) - Japan's Nikkei average extended its losses on Wednesday, slowly heading for a double bottom on charts ahead of earnings results for last business year to be announced in early May, after foreign-driven post-quake rebound looks to have run its course.
Souring the market mood, shares in Tokyo Electric Power Co plunged more than 16 percent, at one point hitting an all-time low of 292 yen on mounting concern the utility is likely to face huge damages payments due to the ongoing crisis at its stricken nuclear power plant.
Blue-chip exporters such as Sony Corp and Toyota Motor Corp failed to benefit from the yen's slide and extended post-quake losses as investors who bought them on cheap valuations after the post-quake sell-off started pricing in disruptions to production ahead of earnings announcements for the business year that ended on March 31.
"The Nikkei is heading for a second dip after the quake, and will likely hit a double bottom between April and June as operating losses for that period, particularly among automakers and electronics firms, are going to be severe," said Masayuki Kubota, a senior fund manager at Daiwa SB Investments Ltd.
"Japanese firms, unlike their European and U.S. peers, issue annual earnings forecasts, and with so many uncertainties they'll either show very conservative estimates or none at all," added Kubota, saying the Nikkei will likely pick up steam in the second half of the business year.
By the midday break the benchmark Nikkei was down 0.2 percent at 9,594.99, while the broader Topix lost 0.9 percent to 839.59.
Support for the Nikkei looms at 9,500, where it settled after the post-quake sell-off, analysts said.
The dollar hit a six-month high of 85.52 yen in Asia trade, but the impact of the yen's fall, normally supportive for Japanese exporters, was seen limited as worries over bottlenecks and disruptions to supply chains prevailed.
"Carmakers and other manufacturers have to be able to produce at full capacity first to really feel its positive impact. That's why they're not surging on the news," said Hiroaki Osakabe, a fund manager at Chibagin Asset Management.
Analysts said that with options prices settling this Friday -- the first time since the quake -- Tokyo stocks will likely come under more selling pressure in the near term.
The Bank of Japan's purchases of exchange-traded funds, which amounted to 18.4 billion yen ($216 million) on Tuesday, under an asset purchase programme adopted to bolster the economy were seen as supporting market sentiment.
Oil-related shares such as Japan's largest oil and gas developer, Inpex Corp , and trading houses such as Mitsui Co lost on profit-taking after oil prices rose on Tuesday to their highest since 2008 on supply concerns.
Inpex fell 1.4 percent to 634,000 yen after having advanced more than 15 percent in March, while Mitsui Co was 2.5 percent lower at 1,462 yen.
Shares of Oriental Land Co , the operator of the Tokyo Disney Resort, fell 2.8 percent to 6,210 yen after the Asahi newspaper reported there is a strong possibility the reopening of the theme park complex will be delayed until at least May.
The company denied the report, saying no decision has been made regarding the reopening of the park, which was closed following the March 11 earthquake and has remained shut amid power shortages in the Tokyo metropolitan area. ($1 = 84.900 Japanese Yen) (Editing by Michael Watson)