* FTSE 100 index down 0.2 percent
* Banks weak as European debt concerns remain
* Clothing retailers knocked by poor H&M results
* Energy issues higher as crude rallies
By Jon Hopkins
LONDON, Sept 29 (Reuters) - Britain's top share index fell back in early deals on Wednesday, reversing opening gains as weakness in banking issues on continuing European debt uncertainties countered strength in energy issues.
By 0836 GMT, the FTSE 100 index was down 11.24 points, or 0.2 percent at 5,567.20, falling back after an opening push above the 5,600 level.
"The index is encountering technical resistance around the 5,600 level and with the month-end approaching, investors are cautious about pushing ahead until further corporate and economic data is forthcoming," said Mic Mills, head of electronic dealing at ETX Capital.
Banks were the biggest drag on blue chip sentiment, with Royal Bank of Scotland falling 1.7 percent, as worries over the debt picture in Europe continued to have an impact, particularly concerns over the future for Irish banks.
Clothing retailers suffered after Swedish peer Hennes & Mauritz saw its third-quarter profits miss forecasts due to weaker-than-expected gross margins.
Marks & Spencer lost 1.1 percent, while Next fell 0.1 percent, and elsewhere in the sector DIY retailer Kingfisher shed 1.4 percent.
Drug issues also fell back, with AstraZeneca the worst off, losing 1.4 percent after RBS cut its rating for the drugmaker to "hold" from "buy".
The broker said that "after a strong run of positive clinical newsflow ... many share price drivers have played out."
Metals group Vedanta Resources was the biggest FTSE 100 faller, down 4.5 percent after its Sterlite Industries unit was ordered by a court to shut its Tuticor copper smelter in south India.
Ex-dividend factors also accounted for a number of blue chip fallers, with Centrica, Inmarsat, International Power, Tullow Oil and WM Morrison Supermarkets all losing their payout attractions on Wednesday.
ENERGY BOOST
Energy issues provided the main underlying prop for the blue chips as crude prices rallied after recent falls.
BP took on 2.2 percent, while BG Group and Royal Dutch Shell both added 0.4 percent.
Royal Dutch Shell told Brazil's oil and gas regulator ANP on Tuesday that it found oil in its subsalt concession block BM-S-54 in the Santos Basin.
Defence firm Rolls-Royce was the top blue chip riser, up 4.1 percent after Morgan Stanley hiked its rating for the group to "overweight" from "equal-weight".
On the macro front, British mortgage approvals for house purchase fell to a seven-month low in August and net consumer credit unexpectedly contracted, according to official data.
The Bank of England said mortgage approvals numbered 47,372 in August, down from 48,346 in July and broadly in line with analysts' forecasts and a weaker industry survey last week.
And consumers unexpectedly made a net repayment of unsecured debt in August. Net consumer credit fell by 120 million pounds, the biggest drop since November 2009. (Editing by Hans Peters)