Footsie has opened lower with the heavyweight sectors of banks and miners both heading south.Speculation over the power struggle at the top of global banking giant HSBC has dominated early proceedings in London. Reports suggest that current chief executive Mike Geohegan will leave at the end of the year after failing to get the job of executive chairman.Meanwhile, the government-appointed Independent Commission on Banking confirmed it will consider whether the major UK banks should split their retail and investment arms or be forced to divest assets to boost competition. Lloyds, Royal Bank of Scotland and Barclays are all lower.Miners are taking a caning led by Kazakhmys, Antofagasta and Anglo-American on fears over metal prices. Sector news is being largely ignored. Mining giant BHP Billiton has received the green light fordevelopment of the Macedon gas field in the Exmouth Sub-basin, Western Australia. Project costs will be in the region of $1.5bn. BHP's rival, Rio Tinto, meanwhile, is to plough $230m into its operations at the Dampier Port in Western Australia to expand capacity. Dana Petroleum's valiant rearguard action against the takeover bid by the Korea National Oil Corporation (KNOC) has failed. KNOC has declared its £18 a share offer wholly unconditional after almost two-thirds of Dana's shareholders backed the deal. The Koreans went hostile a month ago after Aberdeen-based Dana refused their advances, declaring the company worth far more than the £1.8bn on the table. Also on the bid front, Intec is recommending a bid from American firm CSG worth 72p a share in cash, £237m, that the struggling telco billing systems firm believes has a "sound strategic rationale". Business publisher Euromoney is predicting record full-year profits following a recovery in sales during August and September. Wireless products specialist Filtronic's trading in the first quarter has picked up from the weak final quarter of last year, though conditions remain difficult overall. Sales are running at around £1m per month.