RIYADH (REUTERS) - Leading world economies must show unity in dealing with aggressive "tax optimisation" by global digital giants like Google, Amazon and Facebook, G20 officials said on Saturday (Feb 22).

Global rules are being developed by the Organisation for Economic Cooperation and Development (OECD) to make digital companies pay tax where they do business, rather than where they register subsidiaries. The OECD says this could boost national tax revenues by a total of US$100 billion (S$140 billion) a year.