After snapping up a group of ethanol plants on the cheap from bankruptcy proceedings earlier this year, executives with oil major Valero Energy say they may be on the lookout for biodiesel acquisitions, according to the Oil Price Information Service (OPIS).

Valero is looking at opportunities in the animal fat area and views animal-fat-based biodiesel plants as the more economical option. OPIS reports that it's unlikely Valero would be in the market for a plant tied to a soy-based biodiesel process.

Last April, Valero became the first U.S. oil major to take a big step into the ethanol production business when it bought seven large ethanol plants from bankrupt producer VeraSun. The plants represent an annual output capacity of about 780 million gallons.