* FTSEurofirst 300 ends down 0.2 pct, off 1.8 pct in Nov
* Euro STOXX 50 breaks below 6-month upward channel
* Peripheral indexes hammered again by debt worries
By Blaise Robinson
PARIS, Nov 30 (Reuters) - European stocks dipped on Tuesday, struggling to halt a sharp three-week sell-off as investors continued to dump banking shares on mounting fears of a domino effect in the euro zone after Ireland's bailout.
The FTSEurofirst 300 closed 0.2 percent lower at 1,067.22 points, posting a 1.8 percent loss for November, the index's heaviest monthly slump since May.
Peripheral benchmarks took another beating with Italy's FTSE MIB losing 1.1 percent, Portugal's PSI 20 down 1.3 percent, and Spain's IBEX down 0.6 percent.
The Peripheral Eurozone Countries Index fell 1.6 percent, hitting its lowest level since early July.
"There's such a distrust in the euro zone. Long-only investors are turning to German industrial stocks and equities in emerging economies. The only good thing in this crisis for European stocks is the weakening euro," said David Thebault, head of quantitative sales trading at Global Equities in Paris.
Societe Generale lost 3.6 percent, Bankinter dropped 3.2 percent and Banco Espirito Santo fell 2.8 percent.
The euro zone's debt crisis escalated on Tuesday, with investors pushing the risk premium on Spanish and Italian government bonds to euro lifetime highs on fears the region's shaky economies could ultimately be forced to default.
The euro currency dropped across the board, sinking to 2-1/2-month lows against the U.S. dollar, while the VDAX-NEW volatility index, one of Europe's main barometers of investor anxiety, hit a three-month high, adding to Monday's jump after a bailout of Ireland failed to ease investors' fears of contagion.
The euro zone's blue-chip Euro STOXX 50 index lost 0.7 percent on Tuesday to 2,650.99 points, extending its 3-week sell-off sparked by the Irish debt crisis to 8.7 percent. By comparison, the index lost nearly 20 percent in April-May during the Greek debt crisis.
"The index has broken below its uptrend channel and there are no signals of stabilisation at this point, so it's poised to continue to lose ground," said Alexandre Le Drogoff, technical analyst at Aurel BGC, in Paris.
"This pullback cancels the positive scenario for the index developed during the last few months. The next big support level is at 2,560 points, which represents a low hit in August."
On the upside, mining stocks gained ground on Tuesday, rising along with metals prices on persistent concerns about supply tightness.
Rio Tinto and BHP Billiton rose 0.9 percent.
(Reporting by Blaise Robinson; Editing by David Hulmes)