UK Stocks-Factors to watch on August 12

(Adds futures, company news) LONDON, Aug 12 (Reuters) - Britain's FTSE 100 index is seen opening down by around 40 points, or 0.6 percent lower, according to financial bookmakers. Futures were down 0.8 percent ahead of the cash market open. For more on the factors affecting European stocks, please click on * The UK blue chip index closed 1.1 percent lower on Tuesday, led by mining companies and luxury firm Burberry after China devalued its currency, raising the costs of imports