The electricity contract was for the council's larger buildings, including secondary schools and staff offices such as Stopford House, Enterprise House and the Dialstone Centre.
The savings here amounted to more than £150,000. The food contract was tendered along with the other Greater Manchester councils to achieve lower costs.
Councillor Paul Carter, executive member for finance, said, "This successful project is a good example of the council using its skills in the growing e-procurement field.
"We know what is happening in the market place regarding price movements, and were then able to implement our procurement strategy. The e-auction reflects market reality."