* Oils down as crude falls from 10-month peak on U.S. data
* Miners weak; Antofagasta results below forecast
* WPP Group drops as first-half results disappoint
By David Brett
LONDON, Aug 26 (Reuters) - Britain's leading share index was down 0.3 percent at noon on Wednesday as risk appetite wavered in a choppy session, with weakness amongst oil and mining issues offseting strength in pharmaceuticals, beverages and banks.
By 1105 GMT the FTSE was off 15.65 points at 4,901.15 after hitting a near 11-month closing high at 4,916.80 on Tuesday after reassuring economic data from the United States.
The blue-chip index has gained 6.5 percent so far this month and is up 11 percent this year after rebounding 42 percent from an all-time low in March.
Oil majors weighed as crude prices hovered around $72 a barrel after sliding 3 percent from 10-month highs on Tuesday as industry data showed an unexpectedly large increase in crude inventories last week.
BG Group, BP, Royal Dutch Shell and Cairn Energy fell 0.8-2.9 percent.
Tullow Oil sank 3 percent, after the British-based oil explorer reported an 83 percent drop in first-half profit on lower crude prices and production.
"It's been a lacklustre trading session. The market's coming off the boil given the recent impressive rally, with profit taking amongst the mining sector, which has been a tremendous outperformer over the last few months," said Henk Potts, strategist at Barclays StockBrokers.
Miners were weak, with Rio Tinto, BHP Billiton, Kazakhmys and Xstrata losing 0.9-3.1 percent.
Antofagasta was 3.9 percent lower as the Chilean copper miner posted lower-than-expected first-half earnings and said copper prices were likely to remain volatile in the second half.
Citigroup noted that Antofagasta's share price has advanced sharply recently and said it was likely due for a breather.
Rio Tinto said it was likely to open a mine in Serbia in five or six years to exploit jadarite, a mineral used to produce mobile phone batteries.
Amongst individual fallers, WPP dropped 3.5 percent after the advertising group's 8.3 percent decline in first-half revenues disappointed investors, prompting Citigroup to repeat its "sell" rating on the stock.
Meanwhile, ex-dividend factors clipped 0.17 point off the FTSE 100 index, with Eurasian Natural Resources, Fresnillo and InterContinental Hotels losing their dividend attractions on Wednesday.
BANKS, BEVERAGES, PHARMAS WANTED
Banks were higher, with Royal Bank of Scotland performing strongly, up 4.2 percent.
The state-backed lender is poised to slash retirement benefits for staff in an attempt to save 1 million pounds in annual costs and cut future liabilities by 500 million pounds.
Oriel Securities also raised its rating for RBS to "add" from "reduce" in a British banking review. The broker cut its stance on Lloyds Banking Group to "reduce" from "add".
Lloyds Banking Group and Standard Chartered added 3.3 and 1.4 percent respectively.
Diageo, the world's biggest spirits group, was up 2.5 percent ahead of results on Thursday, with Morgan Stanley upping its stance to "overweight" late on Tuesday, with Bernstein also having hiked its stance on the firm.
Brewing giant SAB Miller rose 1.4 percent supported by strong first-half results from Dutch peer Heineken.
Traders went in search of the more defensively perceived stocks, with drugs forms AstraZeneca and GlaxoSmithKline climbing 1.0 and 0.9 percent, respectively.
Among individual gainers, support services group Serco climbed 5.9 percent as it beat market expectations for first-half profit and said it was confident of meeting full year guidance after a strong start to the second half.
Investors were focused on U.S. durable goods data due out later in the session, with futures indexes pointing to a firmer start on Wall Street, with the Dow Jones, S&P 500 and Nasdaq 100 all set to rise 0.1-0.4 percent. (Editing by Dan Lalor)