The world¡¯s biggest growers of palm oil say they¡¯re stepping up efforts to produce the contentious commodity more sustainably, but consumers are unwilling to pay more for environmentally friendly supply.

Production of sustainable palm oil has jumped to a record 13.6 million tons a year, about 20 percent of global output, according to the industry body that certifies the commodity. But only half of that is sold as sustainable oil. That is because it¡¯s more expensive to produce and hardly anyone is willing to pay a premium, says Sime Darby Plantation Bhd., the top planter by acreage.

¡°Buyers don¡¯t want to pay for it,¡± Simon Lord, chief sustainability officer at Sime Darby, said from Kuala Lumpur. ¡°There is increasing resentment among growers that the other actors in the supply chain are not stepping up.¡±