* Focus turns from central bank policy to U.S. politics
* European shares retreat as Deutsche leads banks lower
* Oil prices rebound on OPEC meeting hopes
* Safe haven German bund yields fall
By Abhinav Ramnarayan
LONDON, Sept 26 (Reuters) - European and Asian shares retreated on Monday with investors focused on how Donald Trump would fare in a U.S. presidential debate against Hillary Clinton, while oil prices firmed before an informal OPEC meeting.
Wall Street looked set to open lower, according to index futures ESc1 1YMc1 , before the first of three debates, which was due to begin at 0100 GMT/2100 ET.
Half of America's likely voters will rely on the presidential debates to help them make their choice between Republican Trump and Democrat Clinton in the Nov. 8 election, according to a Reuters/Ipsos poll released on Monday. good performance from Mr. Trump could see market volatility increase, particularly if investors think there is a possibility that he could actually win," wrote Michael Hewson, chief market analyst at CMC Markets in London.
European stocks fell, dragged down by a pullback in the shares of major banking and energy companies. Deutsche Bank shares DBKGn.DE hit a record low. pan-European STOXX 600 index .STOXX fell 1.4 percent and remains down by around 7 percent since the start of 2016.
"We feel that with central bank meetings behind us, the focus will now be more on political risks and so have been spending more time trying to understand the potential implications for a Trump victory," said Mark Dowding, co-head of investment grade debt at BlueBay Asset Management.
He said that while a Trump victory could be seen internationally as bad for global assets, U.S. domestic investors were more sanguine.
Turkish stocks, bonds and the lira sold off on Monday after Moody's slashed its credit rating to junk, against a backdrop of broader emerging markets weakness.
Announcing the downgrade late on Friday, Moody's cited worries about the rule of law after a failed putsch, as well as risks from a slowing economy, in a move which could push up Turkey's cost of borrowing. prices rebounded after Algeria's energy minister said on Sunday that all options were possible for an output cut or freeze at this week's informal meeting of OPEC producers. Brent crude was up 56 cents to $46.45 by 1138 GMT LCOc1 .
MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS extended early losses and was down 0.89 percent, while Japan's Nikkei stock index .N225 ended down 1.3 percent.
Wall Street logged weekly gains but ended with solid losses on Friday. Still, the S&P 500 managed to record its best weekly performance in more than two months after the U.S. Federal Reserve held interest rates steady on Wednesday.
DOLLAR SLIPS
The dollar slipped 0.56 percent to 100.40 yen JPY= , moving back toward a one-month low of 100.100 touched last week.
The euro inched up slightly to $1.1246 EUR= .
Underpinning the greenback, Boston Fed President Eric Rosengren said on Friday that he believed U.S. short-term interest rates should be raised now and warned a decline in the jobless rate below its long-run sustainable level could derail economic recovery. German bond yields fell to their lowest level in more than two weeks on Monday, falling 2 basis points to minus 0.10 percent DE10YT=TWEB . They closed on Friday with their biggest weekly falls since late July.
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