The lacklustre approach was highlighted by Shell, down 9 1/2p to 407p, and BP, off 6p at 467p, despite oil prices rising overnight. Brent was trading six cents higher at $28.35 a barrel for much of the day, but analysts said Saudi Arabia's decision not to open its most promising oilfields to Western companies had damaged sentiment. Brent crude ended the day at $28.32, up three cents.