Mexico has presented guidelines for the country’s first electricity market auction, the latest step in a process that will include a call for bids and the awarding of contracts early next year, official sources said.

For the bid 20-year Clean Energy Certificates, or CELs, and 15-year contracts for generation projects of any kind will be awarded to private bidders.

Mexico is creating a market for tradable CELs as part of its historic 2013 electricity sector restructuring.

The change ended state-owned power company CFE’s monopoly on electricity generation, transmission and distribution activities.