FTSE up 0.7 pct, above pre-Lehman levels

* FTSE 100 gains for fifth-straight session

* Miners rise on firmer metals prices

* Banks, oils retreat after recent gains

By Jon Hopkins

LONDON, Dec 29 (Reuters) - Britain's top share index gained 0.7 percent on Tuesday, reaching levels not seen since before the collapse of Lehman Brothers in September 2008, as strength in heavyweight miners countered weakness in banks and oils.

At the close, the FTSE 100 .FTSE was 35.20 points higher at 5,437.61, a fresh-15 month peak and registering a fifth straight session of gains. Volumes, however, were very light with traders returning only slowly after the festive break.

"Equities are moving inexorably higher," said Henk Potts, market strategist at Barclays Wealth, "with the corporate picture looking good into the year-end even if the macro one remains pretty cloudy."

Miners added the most points to the FTSE 100 index, driven higher by firmer metal prices. Copper hit its highest level in more than 15 months, lifted by looming industrial action in one of the world's top copper mines in Chile. [ID:nN28156122]

Antofagasta (ANTO.L), Lonmin (LMI.L), Vedanta Resources (VED.L), and BHP Billiton (BLT.L) were among the biggest blue chip risers, up 2.2 to 4.0 percent.

Kazakhmys (KAZ.L) put on 1.7 percent. The copper producer has secured a bigger-than-expected $2.7 billion loan from China in a sign of strengthening ties between the two countries, the head of Kazakhstan's state welfare fund said. [ID:nLDE5BS0GO]

Real estate stocks also featured on the blue chip leaders board as bargain hunters homed in on a sector seen by analysts as among the most undervalued.

Britain's largest shopping mall owner, Liberty International LII.L was the top FTSE 100 riser, up 4.9 percent, as people crammed the stores, lured by post-Christmas sales.

Segro (SGRO.L), British Land (BLND.L) and Hammerson (HMSO.L) put on 2.4 to 3.2 percent.

But banks were weaker as a sector, mainly due to falls from heavyweight HSBC (HSBA.L), off 0.7 percent, while Barclays (BARC.L) lost 0.4 percent, both retreating after rallying ahead of the festive break.

Royal Bank of Scotland (RBS.L), however, rose 2.5 percent, while Lloyds Banking Group (LLOY.L) and Standard Chartered (STAN.L) added 1.6 and 1.0 percent respectively.

Oil majors also proved a sectoral drag as crude CLc1 prices slipped back, with BP (BP.L) losing 0.6 percent, Royal Dutch Shell (RDSa.L) flat, and BG Group (BG.L) up 0.3 percent.

Among individual fallers, British Airways BAY.L shed 1.6 percent, dented by concerns about increased airport security as a result of an attempted terrorist attack on a U.S. Northwest Airlines flight over the Christmas period, and with another strike vote by BA's cabin staff looming.

But Smiths Group (SMIN.L), which manufactures airport security equipment, gained 2.7 percent.

The UK benchmark index has rallied about 57 percent since hitting a six-year trough in March and is up about 23 percent for the year, on track for its biggest yearly gain since 1997.

U.S. blue chips .DJI were just 0.1 percent higher by London's close, after U.S. consumer confidence improved more than expected in December, but house prices were flat in October after five months of increases. (Editing by Rupert Winchester)