UK retailer Waitrose has become the latest retailer to make a commitment to use certified sustainable palm oil (CSPO).

The upmarket grocer is aiming to use CSPO in a quarter of its own-label foods "within the next year" and look to convert all its private-label lines to the oil by the end of 2012.

As an interim measure, Waitrose said it would buy GreenPalm certificates while it converts more and more of its products to CSPO.

Premier Foods plc, the UK's largest food manufacturer, and Waitrose rival Marks and Spencer are among those companies to have recently signed up to the GreenPalm programme.

GreenPalm works by giving palm oil producers certified by the Roundtable on Sustainable Palm Oil one GreenPalm certificate for each tonne of palm oil they produce sustainably.

Manufacturers and retailers then bid for and buy the certificates online as a means of helping the production of sustainable palm oil.

Signatories to GreenPalm, including Premier, have stated that they see the programme as a stepping stone to using CSPO, which, campaigners hope, will be supplied in a fully segregated and traceable supply chain.

UK-listed processor New Britain Palm Oil is close to completing the construction of a CSPO refinery in Liverpool that has promised a "dedicated supply source" from its plantations in Asia to the facility.

Last month, United Biscuits, the UK group behind McVitie's and Jacob's, secured a deal for palm oil supplies from the Liverpool site and Premier is in talks with the processor.

Waitrose insisted "very low levels of palm oil" are used in around 1,000 own-brand products, or around 10% of the retailer's total own-label range.

The retailer claimed it is already working to minimise or eliminate palm oil but said that the ingredient is important to the texture of cakes, patisserie, biscuits and sweet and savoury pastry products.

Waitrose will first focus on two of its largest palm-oil containing categories - biscuits and soaps. These two categories account for 25% of the palm oil the retailer uses.

The commitment to move to 100% sustainable palm oil follows a meeting held in London yesterday (2 December) between David Nussbaum, chief executive of green campaigners the WWF, and Waitrose managing director Mark Price.

Price said Waitrose's "mediocre rating" in a recent WWF study into the levels of sustainable palm oil being used by food manufacturers and retailers had "toughened our resolve".

"We can and we will meet this ambitious target. We want to be part of the solution, not contributing to the environmental problems caused by the growth in palm oil use," Price said.