In a letter to the European Union's financial regulation chief, a group of companies objected to a proposal to include reporting not just at government level, but on a project-by-project basis. They said that was commercially and politically sensitive, would not add transparency and the rules failed to define what constituted a project. It was signed by Anglo American , BHP Billiton , Rio Tinto , Xstrata , BG Group, BP , Repsol , Shell , Total.