Vigilante spoke on the sidelines of the organization's event in New York Thursday.

New York-based Rainforest Alliance, an international nonprofit conservation group, certifies farms that meet specific criteria aimed to produce what it calls "sustainable" agricultural products. The process is designed to benefit the environment, farmers and their communities.

Coffee purchases from Rainforest certified farms has grown by an average of 93 percent annually since 2003, when the figure sat at 7 million lbs. In 2007, 91.3 million pounds of certified coffee were bought, Rainforest Alliance said.

In January 2007, McDonald's UK began sourcing all of its coffee from Rainforest farms. Since then, the unit of McDonald's Corp has reported a 22 percent increase in units of coffee sold, Rainforest data showed.

"It will continue to grow at that rapid pace for some years to come because the world is a huge market and it's like a snowball effect," Vigilante said about.

Italy's leading coffee roaster Lavazza buys about 2 million 60-kg bags of coffee annually and was accredited by Rainforest Alliance in 2006. In the United Kingdom, 30 percent of the coffee Lavazza purchases is Rainforest Alliance certified, said Barry Kither, Lavazza sales and market director in the United Kingdom.

"The UK is particularly keen on ethical products," Kither said, noting the trend moves at different paces in different countries.

"For the UK it's a lifesaver because you can hardly talk to a company now without ticking that box, 'Do you have an ethical product available?' We needed it desperately, defensively," Kither said.

The company's overall Rainforest purchases, however, is a small 1 percent, said Mario Cerutti, director of supply chain in Turin.

The trend is global. Privately held Gloria Jean's Coffees International, based in Sidney, Australia, has 850 stores operating in 32 countries with more in the works, said Executive Chairman Nabi Saleh.

Gloria Jean's buys ""several millions of pounds of green coffee" and aims to make 85 percent of these purchases Rainforest certified by 2010, up from the current 45 to 50 percent, Saleh estimated.

Minneapolis-based Caribou Coffee purchases more than 60 percent of its coffee from Rainforest farms, exceeding the company's 50 percent goal for 2008, said Chad Trewick, Caribou's senior director of coffee and tea.

"It's fostered a spirit of partnership, and a slow and gradual transformation in the mind-sets that these producers and communities think about the environment," Trewick said.

Caribou Coffee has eight permanent blends and three seasonal blends bearing the Rainforest seal, he said.

"We really believe that sustainability ... really resonates with a lot of the consumer base and more and more mainstream people are looking for people to make an impact with their purchasing power," he said.