By Chen Aizhu SINGAPORE (Reuters) – PetroChina may sell out from natural gas projects in Australia and oil sands in Canada to stem losses and divert funds to more lucrative sites in the Middle East, Africa and central Asia, two people with knowledge of the matter said. PetroChina’s plan follows a similar strategic shift by smaller state peer CNOOC Ltd, which was preparing to exit its operations in Britain, Canada and the United States because of concerns the assets could become subject to Western sanctions. The sales follow an internal review of PetroChina’s global portfolio that began last ye…