The Greenex index, launched in February 2012, measures the performances of companies in terms of carbon emissions.
It includes top 25 companies based on Green House Gas (GHG) numbers, Free Float Market capitalisation and turnover.
"For GHG emission numbers, stocks which are in between the scale of 50-100 within the sector are assigned a point of 1,000. This ensures that stocks with relatively lower GHG emission numbers in the universe have higher probability of index inclusion," the BSE said in a circular.
'BSE-Greenex', environmental-friendly equity index, initially comprised 20 companies and later increased to 25 in order to give due consideration to the firms, which pro-actively off-set the carbon emissions by planting trees and taking several other initiatives in this area.