* FTSE 100 index set for worst month since July
* Banks fall; European debt worries linger
* Miners rally as metals prices rebound
By Jon Hopkins
LONDON, Nov 30 (Reuters) - Britain's top share index was almost flat around midday on Tuesday as investors remained cautious over euro zone debt problems, with banks the worst performers and miners rebounding alongside metals prices.
At 1153 GMT, the FTSE 100 was up 3.08 points, or 0.1 percent, at 5,554.03, having plunged 2.1 percent on Monday to a level not see since the end of September.
Having hit a near two-month high at the start of the month, a reversal in the past few weeks has put the index on course to lose 2.1 percent in November, its worst monthly performance since July.
"Since the start of November, the FTSE has been forming a clear downward trend ... The level of 5,550 looks key, which it looks to be testing at present, and should it break through this with conviction then you could be looking at 5,250 as a next target," Phil Gillett, a trader at Spreadex, said.
Banks, seen as among the most vulnerable to continued European debt worries, were the biggest drag on blue-chips, with Barclays the worst off, down 1.8 percent.
Worries the euro zone's debt problems may spread beyond Ireland to Spain and Portugal meant investors were reluctant to take positions in riskier assets such as banks.
"Yesterday's market dump over doubts the bailout package for Ireland was sufficient has created an effect which it was trying to stop -- fear spreading throughout the market about a potential domino effect," said Gillett.
Life insurer Standard Life was the heaviest FTSE 100 faller, down 2.1 percent, while fund manager Schroders lost 1.2 percent as financial issues were cold-shouldered.
Integrated oils were mostly lower as crude prices slipped, with BP down 0.1 percent.
BG BUOYED
But BG Group bucked the trend, lifting the overall sector with a 0.9 percent rise as Barclays Capital upped its rating for the firm to "overweight" from "equal-weight."
Explorer Cairn Energy bounced back from sharp falls on Monday, adding 1.7 percent to top the FTSE 100 leaderboard.
Miners rallied as copper prices moved higher after recent falls helped by tight supplies, with Rio Tinto and BHP Billiton both up 0.9 percent.
Gold prices set record highs in euro terms on Tuesday, with African Barrick Gold -- which on Monday said it had found more of the metal in Tanzania -- gaining 1.0 percent.
Broker comment also supported two blue-chip gainers, with cruises operator Carnival adding 1.6 percent after an upgrade in rating by Numis Securities, while telecoms operator BT Group ticked up 1.2 percent as MF Global raised its target price in a sector review, with the firm its top UK pick.
Investors looked to Wall Street's restart to provide further direction, with U.S. stock futures indicating modest falls after a late rally from lows on Monday.
Chicago PMI readings, and U.S. consumer confidence data, due at 1500 GMT, will give further indications of the strength of recovery in the world's biggest economy.
British consumer confidence weakened more than expected in November when people were the most downbeat about the prospects for their personal finances in almost two years, a GfK/NOP survey said on Tuesday.
(Editing by David Hulmes)