The FTSE 100 extended earlier gains in afternoon trading after US economic growth data came in much stronger than markets had expected.
The UK bluechips index was up 1.2%, or 63 points, at 5210 at 1.50pm having been just below 5,200 just before the data.
US futures contracts rose sharply after the data, which showed the world's largest economy growing at a 5.7% annual rate in the last quarter of 2009. That was the fastest pace for more than six years and compared with an average forecast by analysts for a 4.6% annual rise.
Oil prices pushed through $74 a barrel after the figures, while gold and copper also rose.
Those commodity price rises leant further support to UK-listed miners, which are currently taking up most of the top slots on the FTSE 100's strongest risers board.
