* Japan shares bounce back; Europe, U.S. lower
* Yen neared record high against dollar
* Bahrain, Libya concern boosts oil price (Updates with New York open, changes dateline)
By Al Yoon and Jeremy Gaunt
NEW YORK/LONDON, March 16 (Reuters) - European and U.S. shares fell on Wednesday as the nuclear crisis in Japan raised concern of slower growth worldwide, though Japanese stocks rebounded as some investors saw value after a steep sell-off.
Western markets also struggled with trouble in Bahrain and concerns about euro-zone debt.
Wall Street opened lower as the price of oil climbed. Brent crude <LCOc1> rose 2 percent to $110.65 a barrel after Bahraini security forces cracked down on protesters, with fighting in Libya simmering in the background.
"There is a perfect storm of uncertainty right now in terms of global growth, and markets are taking that into account," said Oliver Pursche, president at Gary Goldberg Financial Services in Suffern, New York.
Euro-zone debt worries also surfaced, pressuring the euro. Portugal's 12-month borrowing costs rose at a bill auction after a two-notch rating downgrade by Moody's, showing the debt-laden country remains under pressure despite a euro zone deal to tackle the debt crisis.
Some sectors of financial markets were readjusting after a worldwide battering of riskier assets following the earthquake, tsunami and nuclear disasters that have hit Japan, the world's third largest economy.
"It is too early to say if we are facing a trend reversal or just an interruption of the negative trend, but at least it is a stabilization," said Enid Omerovic, analyst at Frankfurt-based Close Brothers Seydler.
MSCI's all-country world stock index <.MIWD00000PUS> was up half a percent. It fell as much as 4.5 percent over the past three sessions on the back of a near 20-percent, two-session dive on Japan's Nikkei average <
>.Wednesday's recovery was mainly boosted by Asia stocks, with the Nikkei regaining 5.7 percent. It remained down more than 11 percent for the year.
There was widespread belief that the post-earthquake sell-off had gone too far, too quickly, but there was still concern that the nuclear reactor crisis was unresolved.
"Uncertainty in the Fukushima nuclear power plant is clearly making market participants very nervous," said Kazuhiro Takahashi, general manager at Daiwa Securities Capital Markets in Tokyo.
The Dow Jones industrial average <
> was down 50.86 points, or 0.43 percent, at 11,804.56. The Standard & Poor's 500 Index <.SPX> was down 4.22 points, or 0.33 percent, at 1,277.65. The Nasdaq Composite Index < > was down 6.37 points, or 0.24 percent, at 2,660.96.Europe's Eurofirst 300 <
> was flat. Banks led decliners after the Moody's downgrade of Portuguese debt overnight.U.S. and European markets also weakened after the U.S. government reported its producer price index surged at its fastest pace in more than 1-1/2 years in February.
YEN SLIPS
The yen steadied around a four-month high versus the dollar.
Japan's nuclear crisis was seen as triggering more safe-haven yen demand, raising the prospect of intervention to stem big gains.
The dollar <JPY=> traded lower by 0.2 percent, near a four-month low of 80.60 yen hit on Tuesday.
"We wouldn't talk about a recovery in dollar/yen yet," said Lutz Karpowitz, FX strategist at Commerzbank in Frankfurt. A drop under 80 yen isn't expected, however, as authorities are likely to take steps to prevent a steeper yen rise, he added.
The dollar index <.DXY> against major currencies rose 0.39 percent, while the euro <EUR=> slipped 0.53 percent to $1.3922, having failed to break above a four-month high of $1.4036 hit earlier this month.
Portuguese bonds underperformed following the ratings cut and yields rose at the sale of 1-year paper.
Spot gold prices <XAU=> rose $6.40, or 0.46 percent, to $1400.30. (Additional reporting by Akiko Takeda, Antoni Slodkowski, Naomi Tajitsu, Kirsten Donovan, Atul Prakash and Harro ten Wolde; Editing by Padraic Cassidy)