* FTSE 100 index up 2.3 percent in first session of 2011
* BP leads energy issues higher, helped by takeover chatter
* Miners lifted by strength in metals prices
By Jon Hopkins
LONDON, Jan 4 (Reuters) - Britain's leading share index stormed higher by midday on the first session of 2011, pushing back above 6,000 to levels not seen for 31 months, boosted by strength in heavyweight commodity issues and banks.
By 1202 GMT the FTSE 100 index was up 137.89 points, or 2.3 percent, at 6,037.83, easily recouping the 1.2 percent losses it registered on Dec. 31.
"The FTSE 100 has rallied an average of 1.3 percent on the first trading day of the year for the last five years, and so today's rally, whilst expected, is above average in terms of strength and will give investors a nice boost," said Joshua Raymond, market strategist at City Index.
BP was the top blue-chip gainer, up 5.2 percent to a six-month high after the Daily Mail newspaper reported that oil rival Royal Dutch Shell had considered an opportunistic takeover bid for the firm during the Gulf of Mexico oil spill.
Royal Dutch shares gained 1.2 percent, with peer BG Group ahead 3.3 percent as crude prices pushed up towards $92 a barrel, the highest level in more than two years.
Copper prices hit a record high in London on Tuesday, buoyed by positive manufacturing data across the world, with Xstrata adding 4.8 percent and silver miner Fresnillo gaining 4.8 percent.
On Monday, data from the U.S. showed its manufacturing sector grew for a 17th consecutive month in December, while U.S. construction spending increased in November to its highest level since June.
Meanwhile China's factory inflation cooled in December, while manufacturing in Europe accelerated.
But gold miner Randgold Resources missed out on the sector's gains, down 0.7 percent as the price of the yellow metal dipped back after a strong run, hit by a firmer dollar.
LENDERS SUPPORTED
Banks also saw good support, bouncing higher as worries over euro zone sovereign debt faded further into the background, with Royal Bank of Scotland adding 4.7 percent and Barclays up 3.5 percent.
An Exane BNP Paribas upgrade to "outperform" also helped RBS, with the broker saying a sharp sell-off on the bank's exposure to debt-hit Ireland presents a buying opportunity.
Among individual blue-chip gainers, Carnival Corp. took on 4 percent after being upgraded to "buy" from "hold" by Deutsche Bank with an increased target of 3,700 pence.
There were few main board fallers. Main losers were stocks seen as defensive, as investors' risk appetite returned. Food producer AB Foods was down 0.3 percent, while utility International Power sipped 0.1 percent.
British manufacturing activity grew at its fastest pace in more than 16 years in December, and firms' costs rose at a record pace, suggesting at least one sector of the economy may be ready for higher interest rates before the end of 2011.
And British mortgage approvals rose unexpectedly in November to their highest since July while unsecured consumer lending suffered its biggest monthly fall since August, Bank of England figures showed on Tuesday. (Editing by Sharon Lindores)