Greenpeace has launched a guide for transgenic foods in Mexico, the first of its kind in the country where food manufacturers are not obliged to disclose their use of genetically modified compounds.

The guide splits 250 products into a green and red list: green for transgenics free, red for companies that use transgenics or whose status remains ambiguous, a Greenpeace spokesman said.

To prepare the guide, Greenpeace officials interviewed Mexico's 50 biggest food companies to find out their transgenics profile.

Companies in the green list include local and international players such as Pascual, Alpura, Gerber and Chocolates Ferrero.

Sara Lee-owned bakery goods giant Bimbo, Nestle, Clemente Jacques, Laposse, McCormick, Herdez, La Costena and La Sierra are some big brands on the red category.

"We lobbied hard for years but the companies beat us and we don't think there will be a [disclosure] law anytime soon," the spokesman said. "There is an increased sensibility about transgenics in Mexico and we wanted consumers to know what they are eating."

Greenpeace also has transgenic food guides in Argentina and Brazil.