* Oils, miners weak on lower crude, metal prices
* Barclays falls 4.1 percent, confirms $13.5 bln BGI sale
* Pharmaceuticals supported; flu pandemic boost
By Jon Hopkins
LONDON, June 12 (Reuters) - Britain's top share index lost 0.5 percent on Friday as weakness in heavyweight commodity stocks offset gains from pharmaceuticals, with investors still cautious on the prospects for a sustained economic recovery.
At the close, the FTSE 100 was 19.92 points lower at 4,441.95, giving back much of Thursday's 0.8 percent rise but not far away from last Friday's closing level of 4,438.56.
The index is still up around 29 percent since hitting a six-year trough in March but has held in a tight range between about 4,400 and 4,500 for the last month.
"Equities are once again dead in the water with no meaningful moves in either direction on all the world's major stock markets, said David Evans, market analyst at BetOnMarkets.com. "Markets have gone from extreme volatility to dead calm this week."
Oil majors fell after the price of crude retreated below $72 a barrel, ending a three-day rally. Oil peaked at over $73 on Thursday, its highest since Oct. 20.
BP, Royal Dutch Shell, BG Group, Tullow Oil and Cairn Energy were down between 1.0 and 2.9 percent.
Mining stocks were a big drag on the index as metal prices weakened, with Vedanta Resources, Fresnillo, Antofagasta, Kazakhmys, and Anglo American falling 1.9 to 8.5 percent.
Shares in Rio Tinto and BHP Billiton shed 1.3 and 2.1 percent respectively after Australia's government gave cautious support for the two miners' planned iron ore joint venture but a newspaper reported that China had threatened sanctions against the two if the deal went ahead.
Barclays fell 4.1 percent after it confirmed it is to sell its investment arm BGI to BlackRock for $13.5 billion in a blockbuster deal that will create the world's biggest asset manager.
Most other banks were lower, with HSBC, Lloyds Banking Group and Standard Chartered losing between 0.2 and 2.2 percent, although Royal Bank of Scotland gained 0.5 percent.
Insurers were weak following a slightly cautious review from ING, with the broker saying although they are doing well, a re-rating of the sector is unlikely.
ING cut its rating for Prudential, down 1.8 percent, and for Legal & General, off 0.6 percent.
DRUGS DO WORK
Drug companies added the most points to the index as investors shifted assets into the defensive sector a day after the World Health Organisation declared the H1N1 influenza virus a pandemic and warned governments to prepare for a long battle against it.
H1N1 vaccine-maker GlaxoSmithKline rose 5.4 percent, also supported by Thursday's Morgan Stanley upgrade.
GlaxoSmithKline is planning to cut prices of many of its leading medicines in emerging markets, CEO Andrew Witty told the Financial Times.
Peer Astrazeneca rose 4.5 percent helped by a UBS target price hike, while Shire added 0.5 percent.
BT Group was also a big blue-chip gainer, up 4.1 percent after Bank of America Merril Lynch upgraded the telecoms group to "buy" from "neutral" and increased its target price.
Peer Cable & Wireless added 1.3 percent.
The Bank of England said it is still too early to tell what the impact of the 125 billion pound asset buying spree it embarked on is having on the economy.
It also said more than one in 10 British households may have fallen into negative equity, similar to levels seen in the mid-1990s.
"It's been a very interesting week, we have had some good momentum and now it is time for perhaps a little bit of stagnation," said Howard Wheeldon, strategist at BGC Partners (Editing by Hans Peters)