The FTSE stock index traded higher at midday on Friday, with miners boosted by a sharp rebound in copper prices as signs of economic growth in the United States helped bolster optimism over demand for the metal.

At 1224 GMT, the FTSE 100 <.FTSE> was 28.17 points, or 0.5 percent higher, with volume on the index showing a slight pick-up from yesterday's low levels, but traders are braced for a further dip in the days and weeks to come.

I can't imagine the gains that we had are going to be held on to, Richard Maguire, head of derivative trading at Daniel Stewart, said.

The focus sooner or later is always going to turn back to the euro zone and it's not going take much for the yields to spike again.

Greece announced on Friday it will auction 1 billion euros of three-month bills in what some traders see as the last crucial market diary item before the Christmas break.

MINERS RALLY

Copper specialist Kazakhmys and Antofagasta led the charge, both up around 4 percent, as the copper price, which is highly sensitive to economic activity, reversed a fraction of its recent losses, supported by data released yesterday that showed the U.S. economy is recovering.

It's probably a technical rebound. People are clearly destocking now, Andy Davidson, a mining analyst at Numis Securities, said.

Three-month copper contracts on the London Metal Exchange were still headed for the biggest weekly loss since the end of September and the first annual decline in three years, on concerns about deteriorating economic conditions in Europe and slowing growth in big consumers of metal, such as China.

Adding support to the sector, UBS recommended gaining exposure to miners after their recent share price de-rating and Liberum Capital said value remained apparent.

Shares in banks <.FTNMX8350>, up 1.1 percent, also extended their rebound from Wednesday's sell-off, although sentiment was subdued after Fitch downgraded Barclays and six other global lenders late on Thursday, citing increased challenges in the financial markets due to economic developments as well as a myriad of regulatory changes.

Providing further evidence of how the crisis is making life harder for investment banks, European dealmakers expect mergers and acquisitions activity to be flat at best next year, even if measures agreed to at last week's EU summit restore confidence that the continent can overcome its debt crisis.

The media sector underperformed, weighed down by BSkyB , down 1.5 percent, which was downgraded by Bank of America-Merrill Lynch on cost and competition concerns.

The broker also downgraded Anglo-Dutch publishing group Reed Elsevier , down 0.6 percent, citing lack of new catalysts after a strong run, while it upgraded best of breed Pearson
, sending the stock 0.9 percent higher.

(Editing by Andrew Callus)