STOCKHOLM, SWEDEN --- Swedish refiner Preem unveiled plans to start making biodiesel from pine tree oil, a lumber industry waste product, in response to criticism about the effect of biofuel on food prices, Reuters reported.

Preem, which is privately owned, said it would work with forest owners Sodra Skogsagarna and Sveaskog to finance a plant to produce pine tree oil as a biodiesel feedstock.

Preem will also modify its crude oil refinery in Gothenburg to refine the pine tree oil, as well as vegetable oils and animal fats, into biodiesel. Preem spokesman Thomas Ogren told Reuters that the Gothenburg refinery would start off by refining pine tree oil.

"The adjustment of the refinery will be done by the end of 2009 and [it] will then be able to refine 140,000 tons of green raw material per year," Preem said in a statement. "In order not to compete with food production, Preem will in the first place use forestry-based commodities."