* FTSEurofirst 300 index flat, near six-month closing high * Commerzbank slips as Q3 profit misses expectations
* Siemens rises ahead of update
By Brian Gorman
LONDON, Nov 8 (Reuters) - European shares were flat on Monday, near six-month closing highs, as positive momentum from last week was offset by renewed worries about euro zone debt, strengthening the dollar and hurting commodities prices.
The pan-European FTSEurofirst 300 index of top shares fell 0.04 percent to close at 1,110.85 points after hitting its highest close since mid-April on Friday when it was boosted by U.S. jobs data and monetary stimulus plans.
The European benchmark is up more than 72 percent from its lifetime low of March 2009, with several major economies having emerged from recession helped by stimulus from governments and central banks worldwide. The euro fell broadly on Monday on renewed concerns about euro zone peripheral debt while Friday's solid U.S. jobs data supported the dollar.
A rising dollar makes commodities priced in the U.S. currency more expensive for holders of other currencies. Among miners, Anglo American and Xstrata fell 2.4 percent and 1.4 percent respectively.
"Sentiment indicators for the short term are quite extended, so there is a chance there will be a pullback," said Graham Secker, European equity strategist at Morgan Stanley.
He said euro zone debt was a "possible catalyst for a correction", adding the correction would be short-lived.
Financials and commodities were likely to be among the strongest performersh said. "The miners have had a great run but they are still not particularly expensive."
The STOXX Europe 600 basic materials sector index, which includes miners, is up 18 percent this year. On the upside on Monday, German industrial group Siemens rose 1.4 percent. The company may reveal new strategic targets this week paving the way to return capital to investors through a higher dividend.
German sporting goods retailer Adidas gained 1.6 percent after saying it aimed to overtake market leader Nike by increasing sales to 17 billion euros ($24 billion) by 2015.
COMMERZBANK FALLS
Commerzbank, Germany's second-biggest lender, fell 5.2 percent after missing third-quarter profit forecasts as losses on commercial mortgages and the cost of integrating Dresdner Bank offset strong corporate lending.
Broker downgrades left utility makers lower. Scottish & Southern Energy slipped 1.6 percent after Nomura cut its rating on the stock to "reduce" from "neutral". E.ON fell 1.2 percent after Nomura downgraded it to "neutral" from "buy".
Across Europe, the FTSE 100 index ended the day 0.4 percent lower; Germany's DAX and France's CAC 40 both fell 0.1 percent.
Spain's IBEX fell 1.3 percent, with bank BBVA among the fallers, down 1.5 percent.
Bank of Ireland fell fell 4.2 percent, having been down more than 12 percent at one point. Ireland is trying to convince the markets it does not need a Greek-style bailout.
The country's main opposition party said on Sunday it would not back next month's budget.
"If it is Ireland or Portugal, it could be idiosyncratic," Secker said. "But if it is Spain it could be systemic. If one of the effects of QE (quantitive easing) is to weaken the dollar and strengthen the euro, it is the peripheral countries that are least able to handle a stronger euro."
Greek banks rose 2.5 percent, on relief George Papandreou decided not to call early national elections.
The Thomson Reuters Peripheral Eurozone Countries Index fell 1 percent.
Wall Street was slightly lower around the time European bourses were closing. (Editing by Dan Lalor)