PULLY, Switzerland — In a coffee-scented conference room near Lake Geneva, Ramon Esteve, a sixth-generation commodities trader, sits amid his father's collection of centuries-old grinders and explains why he's helping impoverished farmers grow more coffee, cotton and cocoa.

He's embracing a goal, first laid out by fair-trade activists, so he can secure more sustainable supplies for his company and clients such as Nestlé, the world's largest food company, and Starbucks, the biggest coffee-shop operator.

"For us it was survival," said Esteve, chairman of Ecom Agroindustrial, one of the largest coffee traders. "We're not philanthropists. We're businessmen."

Esteve's blunt acknowledgment shows how a mission-driven movement is transforming into a corporate push for productivity and profit.

The cause begun in the 1980s by a Dutch priest and his activist-acolyte to help coffee farmers in Mexico's Oaxaca state now includes some of the world's biggest sellers of coffee (Nestlé), lingerie (Limited Brands), chocolate (Cadbury) and bananas (Wal-Mart), to name a few.

New research has quantified the benefits to the bottom line. In a study released last year, researchers at the Massachusetts Institute of Technology, Harvard University and the London School of Economics found they could boost bulk coffee sales by 10 percent just by adding a fair-trade label on the packages.

Sales of goods approved by Fairtrade International, the world's largest certifier of such products, soared 27 percent in 2010 to more than $5.7 billion.

The push to increase sales of goods deemed to be free of child labor and other practices has divided the movement, raised questions of whether going mainstream will undermine the cooperative farmers it was created to help and, most of all, strained the integrity of the certification systems vouching for the fair-trade stamps that allow companies to charge consumers more.

"The fair-trade movement has profoundly lost its way," said Aidan McQuade, who has advised Cadbury on cocoa buying as director of Anti-Slavery International, a human-rights organization founded in 1839. "Its focus on volume — unless they have got all their systems in place to address fundamental issues like ethical trade, child labor and child slavery — is problematic."

The strains are evident in the work of Germany-based Fairtrade International, a network of 25 organizations that certifies more than 100 products from cotton to gold around the globe. The labeling group approved cotton in a Burkina Faso program that Bloomberg News recently found is using child labor.

That program supplies fiber to Limited Brands' Victoria's Secret division, which said it is investigating the issue.

The problems illustrate the difficulty in broadening the reach of ethical commerce.

"To spread the benefits of fair trade, we have to mainstream. It's challenging, but we are determined to do that with integrity," said Barbara Crowther, spokeswoman for the Fairtrade Foundation, a nonprofit that licenses use of the Fairtrade brand in the U.K. "We have done a huge amount to improve and strengthen and professionalize the certification system, and we are still working on it."

Popularity becomes issue

The group's struggles to police its own system come as the number of so-called ethical labels has mushroomed. The creation of 202 new ones in the past decade boosted the total tracked by Ecolabel Index to 424. That includes those created by companies, such as Starbucks's own stamp for its producers, CAFE Practices.

The growth has thrown into question the very definition of fair trade and exposed rifts between the movement's founders.

What evolved into Fairtrade International began in 1985 with the Dutch missionary priest, Frans van der Hoff, and a trade-campaigner friend, Nico Roozen.

The pair developed a system where farmers were guaranteed a minimum price and a social premium to be used for projects such as health clinics and schools. They dubbed their label Max Havelaar, after the idealistic Dutch colonial officer in a 19th-century novel about the coffee trade.

Fairtrade International still uses their model, paying farmers premiums totaling $164 million from 2007 to 2010. It estimates 1.15 million farmers and workers were in the system in 2010.

Today, van der Hoff and Roozen are at odds over how best to help producers amid the surge in demand for fair-trade goods.

"The two founding fathers of the movement are taking different positions," said Roozen, the son of a tulip farmer. "He is criticizing fair trade because it is making compromises with big companies like Nestlé. And I am criticizing fair trade because they haven't taken the lead in mainstreaming fair trade."

Farmers must be trained to partner with major corporations so they can boost volume, said Roozen, director of the Dutch nonprofit Solidaridad. He works with Ecom. They say they can offer farmers better prices and help in boosting yields without a formal fair-trade system.

Van der Hoff and his allies say corporations will offer those prices only until fair-trade cooperatives wither and die.

"It just ends in fair-washing and smoke screens," said van der Hoff, who still lives with the Oaxaca farmers he started helping three decades ago. "They are deceiving themselves."

Different companies use different language — fair trade, sustainability, shared value. They say they're working toward a similar goal: improving the quality of farmers' products and lives.

Ecom is expanding programs to help farmers improve their harvests because it has seen its supply base dwindle when growers don't make enough money.

"What do you do to keep them on the land? You train them," said Esteve, who lives in Switzerland. "These people could easily, easily double their yields by enrolling in these programs and following the best practices we are trying to promote."

Case in Mexico

The future of fair trade boils down to Roozen's and van der Hoff's rival visions. A test of their arguments can be measured in southern Mexico, birthplace of the fair-trade labeling movement and the center of its burgeoning organic-coffee production.

It's here that Juan Carlos Lopez, an adviser to the Cafi Guerrero Maya cooperative in Chiapas, said he can quantify the cost to farmers if big companies win the day. The difference between the market price for coffee and prices paid for Arabica beans by intermediaries buying for Ecom's Mexico unit, known as Amsa, amount to at least 30 percent of a farming family's revenue, he said.

"All they do is buy it cheap and sell it at a high price," said Lopez, now an economics student at a university in Mexico City.

Lopez got his start in the coffee business on his father's farm, wielding by age 8 a worn machete as long as his arm to clear weeds in the Chiapas mountains. Sixteen years later, Lopez is on a mission to cut out the middlemen coyotes by linking his father's cooperative to the fair-trade movement.

The cooperative found buyers this year in Mexico City who paid 72 pesos ($5.20) per kilogram after transport and processing costs, compared with about 50 pesos per kilogram in Chiapas.

Lopez is skeptical that Amsa will aid producers in Chiapas, where for decades poor wages meant indigenous families lacked access to enough health care, food and schooling.

His family and the more than 200 other indigenous producers who make up the Cafi Guerrero Maya cooperative aim to open a chain of shops modeled after fair trade that would sell coffee beans purchased directly from farmers. Such moves could transform lives otherwise spent toiling in the fields, Lopez said.

"It might mean not having kids work, and sending them to school instead," he said. "They could have breakfast, shoes, whatever they need."