Blue chips are trading not far off their best levels of the day, still led by mining stocks and supported by a decent start on Wall Street.A rash of merger and acquisition activity over here is replicated in the US, getting investors in buying mood in the absence of any major economic news.Oilfield services mid-cap Wood Group is buying rival PSN for $955m (£607m). PSN will be merged with Wood's production facilities business, creating Wood Group PSN. It will be run by PSN's chief executive Bob Keiller who'll also join the board.In a separate statement, Wood reported continued progress at most of its key divisions and thinks the overall performance for 2010 is likely to be slightly ahead of expectations.Elsewhere in the sector, Wellstream rallied after US giant General Electric announced a £785m deal to buy the company, upping the price from 750p a share plus to 780p plus a 6p dividend.Among the large caps, household products group Reckitt Benckiser has agreed to buy privately owned Indian firm Paras Pharmaceuticals for around £460m. Reckitt, the owner of famous brands including Finish dishwasher tablets and Harpic limescale remover, said it would finance the transaction from existing facilities.Miners ENRC, Kazakhmys and Xstrata are among the best of the risers as copper hits new highs on the London Metal Exchange.Capital Shopping Centres (CSC) has given short shrift to a proposal by David Simon, chairman and chief executive of US Mall owner Simon Property, that the US group subscribes to a sale of up to 205.5m of Capital Shopping shares priced at 400p each to fund the £1.6bn Trafford deal. "Completely impracticable," is CSC's response.Banknote printer De la Rue has appointed Tim Cobbold as chief executive and an executive director of the company, starting in January. He joins De La Rue from Chloride Group. His first job will be to see off the bid attentions of French group Oberthur.Yule Catto has roared ahead on an agreement to buy PolymerLatex for a total transaction value of €443m (£376m). A 4-3 rights issue to raise £225m will help pay for it.ITV shares picked up after reported bumper ad revenues for the final of X Factor, which was won by Matt Cardle.Mattress and sofa company Airsprung said sales for the six months ended 30 September 2010 fell by 12.8% as it struggled against a very difficult retail environment for beds and furniture.