London has opened lower despite another good day on Wall Street as Nasdaq hit an eleven-month high.Oil and gas explorer BG Group revealed more good news from Brazil an excellent test drill on its 30% owned Guara discovery in the Santos Basin off the coast of Brazil. The discovery is estimated to contain recoverable volumes of 1.1bn to 2.0bn barrels of oil equivalent.Ex-dividend stocks are proving a drag with Diageo top among a list of FTSE 350 companies going ex today. Sportswear retailer Sports Direct said trading levels since July have been ahead of last year and expects underlying operating profits for the current financial year will exceed £150m. Group revenue for the 13 weeks to 26 July 2009 rose 10% to £375m while gross profit improved to £157m from £150m.London and south-east focused housebuilder based Berkeley reports the recent steadying in the housing market has continued with cancellation rates at normal levels and forward sales maintained above £600m in the first four months of its current financial year. Berkeley added it does not expect any land write-downs and had net cash in excess of £300m at 31 August. Strong overseas growth helped contracts for difference specialist IG Group lift revenue by 28% in its first quarter to £68m from £53m. Excluding the impact of FXOnline Japan KK, organic revenue growth was 17%, IG added, while the charge for doubtful debts in the period was less than 1% of revenue.Micro Focus shares slumped as Stephen Kelly, chief executive of the legacy software specialist, announced he is to step down for personal reasons. The firm said a search for a successor will commence immediately, adding that Kelly will work with the board and the broader management team to ensure a smooth and well managed transition of his responsibilities.