Abstract:  Seeking to increase transparency in the public sector, electronic trading has become widely discussed at municipal levels, as a way to enhance efficiency, transparency, economy and celerity in public spending. In this perspective, this study aims to analyze the contributions of the electronic bidding to improve the purchase of common goods and services, and consequently, enhance the efficiency and quality of public spending. The performance analysis of different methods has revealed the average percentage of savings afforded by bidding modalities. The study concluded that electronic trading is a tool against opportunistic behavior of contractual agents, because it hinders the formation of cartels, corruption and fraud thus contributing to the efficiency in the municipal public spending.    Key-Words : Public Administration, Transparency, E-government