The sale of publicly-owned oil, gas and minerals can have a significant impact on the development trajectory of resource-rich developing and emerging economies due to the large volume of commodities sold and the amount of money involved. Therefore, getting the buyer selection process right is a crucial step to prevent potential public revenue losses that can arise through sub-optimal allocation and corruption. This Guidance is intended to strengthen state-owned enterprises (SOEs)’ capacity to market commodities and optimise the value of resources sold. It explains how SOEs can set up transparent and competitive buyer selection procedures that reduce discretion, close opportunities for favouritism and corruption, ultimately leading to increased revenues for improved development outcomes. Based on the review of existing selection and procurement processes, the Guidance provides recommendations for countering key corruption challenges at each step of the buyer selection process, and identifies examples of best practices. This Guidance complements the work of the Extractive Industries Transparency Initiative (EITI) on recommended disclosures of buyer selection procedures by SOEs.