07/04/2010 (Reuters), Paris - Members of the Roundtable on Sustainable Palm Oil (RSPO) said they have increased purchases of certified production to accelerate an initiative hit by charges that palm oil is harmful for health and the environment.

Unilever, the world's top palm oil buyer, said on Wednesday it would more than double this year to 400,000 tonnes its purchases of production certified as sustainable.

Retailer Carrefour said it would buy this year palm oil certificates for an equivalent volume to the palm oil used in its own-brand grocery products in France -- some 10,000 tonnes -- to encourage its suppliers to adopt the scheme.

The RSPO member companies were speaking at a debate at Thomson Reuters' offices in Paris in the midst of a row over whether palm oil is causing deforestation in Indonesia, the world's No. 2 producer of the vegetable oil.

"This is an aspect of the palm oil industry that has to change," said Gavin Neath, Unilever's senior vice president, global communications and sustainability.

Unilever was using a "carrot and stick" approach to palm oil suppliers, encouraging sustainable practices by buying certified production at a premium, while freezing business with Indonesian firm Sinar Mas in response to allegations it was responsible for deforestation, Neath said.

A Unilever spokesman in Indonesia said separately on Wednesday the group could resume purchases if auditors cleared Sinar Mas of the allegations.

The certified palm oil sector has been plagued by weak demand due to the higher cost involved and represents barely 5 percent of overall palm oil output.

But data on the RSPO's website showed rising purchases of certificates this year, almost matching sustainable production in January and exceeding it for the first time in March.

Neath said the RSPO needed to develop faster to meet environmental concerns and to allow full traceability in the supply chain. Certificates do not currently enable end-users to know whether their palm oil has come from sustainable sources.

Unilever also ran full-page advertisements in the British press on Tuesday to promote its use of certified palm oil.

In France, controversy over palm oil has been further fuelled by criticisms of its saturated fat content, which some say make it an unhealthy ingredient for everyday food products.

Carrefour said it would replace palm oil in own-brand lines where there were better alternatives, as it did previously by switching to sunflower oil for its crisps, but was not planning a complete phase-out like rival retailer Casino.