Footsie has opened lower though losses so far are not anywhere near the scale seen on Wall Street and Asia overnight.Concern over the state of the eurozone economy may mean more weakness later but for now investors seem happy to wade through an avalanche of results and trading updates.Oil groups are among the best performers led by Royal Dutch Shell. Higher oil prices helped the company post a sharp rise in earnings in the first quarter of 2010. Profit jumped to $4.9bn on a current cost of supplies (CCS) basis from $3.3bn last year. There was a strong improvement in upstream profit to $4.4bn, although downstream earnings fell to $743m from $1bn. BP and Tullow are also higher.British American Tobacco did well in the first quarter despite weaker volumes, helped by last year's acquisition of Indonesia's Bentoel and currency moves. The world's second largest tobacco company said revenue for the three months grew in constant currency terms across all regions, but volumes dropped to 168bn from 170bn in 2009.Sales rose but underlying profits fell last year at Home Retail as weak consumer spending and higher product costs put pressure on margins at Argos, though Homebase staged a recovery. Sales rose 2% to £6.02bn in the year to February, but discounts and promotions took their toll on underlying profits, down to £293m from £328m.Rolls-Royce remains on track for the full-year after trading in line with expectations since the start of 2010, although business is still challenging and the volcanic eruptions in Iceland haven't helped. Chief executive John Rose still thinks the aircraft engine maker can double revenue over the next decade.Speciality chemicals supplier Croda reported better than expected first quarter results as robust trading continued and is confident of significant progress for the remainder of the year. Pre-tax profit from continuing operations almost doubled to £42.4m from £21.7m in 2009.A strong performance from its rail arm has prompted Stagecoach to upgrade its forecasts for the year, with earnings per share now expected to come in at 17.5p at least. Brewer and pub operator Greene King reported strong trading for the 49 weeks to April 11, with higher sales from its more food-orientated managed operations helping to offset weakness at leased pubs.Satnav systems supplier Trafficmaster is in discussion over a possible bid, it said today.