A group of some of the UK's largest companies has called on the British government to do more to help them reduce CO2 emissions, which are blamed for global warming. The group, which includes oil giants BP Plc and Shell, utility Scottish Power and bank HSBC, said in a letter to Prime Minister Tony Blair on Friday they wanted clearer policy and more incentives...Other signers of the letter included top executives from bank Standard Chartered, water utility AWG, airports operator BAA, speciality chemicals manufacturer Johnson Matthey and F&C Asset Management, which this week called on Exxon Mobil at its shareholders meeting to rethink its policies on climate change.