Public procurement accounts on average for 13 % of GDP in OECD countries. It is particularly vulnerable to fraud and corruption. Fighting and preventing bidder’s cartels and corruption can generate huge welfare gains to societies. This seminar will introduce OECD instruments such as the Guidelines for Fighting Bid-rigging in Public Procurement and the Recommendation on Public Procurement. Competition authorities are well placed to play an important role in fighting bid rigging and corruption – by making extensive advocacy efforts and taking vigorous enforcement action, in co-operation with other relevant state actors. Together with international experts in this domain and with experts from FAS Russia we will exchange experiences and foster a better understanding of mechanisms and symptoms of bid rigging and corruption and the instruments for fighting them.