U.S. retailers are leading the way in sustainability as the likes of Macy's, Nordstrom and electrical outlet Best Buy were added to index provider FTSE's list of leading environmentally and socially responsible firms.
The department stores, along with media conglomerate Time Warner, were among the groups added to the FTSE4Good Index series, which measures companies' environmental, social and governance (ESG) practices, making it easier for investors to identify companies with sustainable practices.
Some 46 companies have been added to the series since its last review in March. FTSE4Good is also used as a basis for tracker funds and structured products. Of the new companies, retailers lead the way, adding seven new companies.
Retail analyst at Neev Capital, Rahul Sharma said retailers should be in the driving seat when it comes to environmental and sustainable practices as they tend to be people-intensive and big employers.
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"The biggest driver for going green is a return on capital as well as ethics. For department stores, usually score well on criteria like energy consumption and risk management," Sharma told CNBC.
"I wouldn't be surprised if this were down to a bigger push on energy lighting, switching off lights, waste treatment and minimising use of materials such as paper and plastic, anything which also has a cost focus," he said.
FTSE Group said the largest number of additions came from the U.S., which contributed 11 companies followed by five from the U.K.
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The changes will be implemented at the close of business on 19 September and will take effect from the start of trading 22 September.
—By CNBC's Jenny Cosgrave: Follow her on Twitter @jenny_cosgrave