The latest league table of the Carbon Reduction Commitment ranks almost 3,000 organisations on their energy performance for the year 2011/12.
The table shows companies have made an average 7% improvement in carbon emissions per unit of turnover. However, only 1 in 4 companies actually reduced their emissions in real terms last year.
Between them, participants in the CRC remain responsible for over 10% of total UK greenhouse gas emissions.
The top 10 emitters accounted for 16% of the total and include Tesco, the MoD and Esso.
For more information, please visit the Environment Agency website.