text: Shares in miners rebounded as investors looked for bargains following recent falls in the sector.
  Sentiment was also helped by upbeat economic data from China - the world's largest importer of raw materials.
  BHP Billiton rose 3.3% and Rio Tinto was 3% higher. The two firms topped the FTSE 100's risers board, with the index up 28.67 points at 6,715.24.
  Shares in the London Stock Exchange rose 2.2% after it reported a 16% rise in half-year operating profits to Â£239.4m.
  The group's results were boosted by the contribution from the US Frank Russell business, which it bought last year and combined with its own FTSE index business.
  Legal & General shares rose 1.8% after the insurer reported an 18% rise in operating profits to Â£750m in the first half of the year.
  Ryanair shares were up 1.6% after the company said that in July it became the first airline to carry more than 10 million passengers in a month.
  Ryanair said it carried 10.1 million customers last month, up 11% from a year earlier.
  On the currency markets, the pound rose 1.6% against the dollar to $1.5589, and climbed 0.3% against the euro to â‚¬1.4350.
target: (Noon): The market remained in positive territory during lunchtime trade, with mining shares among the top risers.