* FTSE 100 index rises 0.3 percent
* Miners up on higher metals, JPMorgan's bullish view
* BSkyB falls, confirms talks over assets in Germany, Italy
By Atul Prakash
LONDON, May 12 (Reuters) - Britain's top share index advanced on Monday morning, with mining companies leading the market higher as metals prices rose and JPMorgan upgraded the sector.
The UK mining index rose 1.8 percent to a one-month high after JPMorgan raised the European mining sector to "overweight" from "underweight". The bank said it saw signs activity was rebounding and the companies were cutting costs.
A rise of up to 4 percent in key industrial metals prices on supply concerns and short covering also helped the mining index. Rio Tinto rose 2.4 percent and BHP Billiton 1.8 percent.
They helped the FTSE 100 index gain 0.3 percent to 6,831.84 points by 0807 GMT, after a 0.4 percent decline on Friday. It had risen to a peak of 6,840.37 on Thursday, its highest since late February.
Analysts said the gains could be capped by geopolitical concerns and a mixed earnings season, but the longer-term outlook remained positive.
"Macroeconomic indicators are showing that the UK is continuing to grow quite rapidly, but tensions in Ukraine are influencing appetite for risk and some of the earnings numbers coming out of both Europe and the UK have been quite mixed," Daniel McCormack, strategist with Macquarie, said.
"The lack of delivery on earnings is one reason why the market is struggling. Longer term, there is still quite a bit of upside to come because I do think that earnings will improve. We have still got scope for an earnings-driven rally on a 12 to 18-month view."
According to Thomson Reuters StarMine data, 51 percent companies on the STOXX Europe 600 index have so far missed analysts' forecasts for the first quarter.
But the UK market is likely to get support from improving economic outlook. The Confederation of British Industry, the top business lobby, upgraded its growth forecasts for this year and next and said it expects to see marked improvements in business investment and productivity.
Among other movers, British Sky Broadcasting fell 2.4 percent after saying it was in early talks with Rupert Murdoch's 21st Century Fox over the possible acquisition of its pay-TV assets in Germany and Italy, Sky Deutschland and Sky Italia. (Reporting by Atul Prakash; Editing by Larry King)