MONTREAL (AFP)--Canadian consumer and environmental groups protested Thursday the government's decision to allow the sale of a genetically modified corn.

The Canadian Biotechnology Action Network, or CBAN, demanded that Ottawa "immediately withdraw authorization for SmartStax," a genetically engineered corn, "until Health Canada undertakes exhaustive and independent tests."

Greenpeace Canada also raised concerns, saying: "Releasing 'SmartStax' without evaluating safety, just a day after the release of the blistering report on the listeriosis crisis, confirms deep structural problems and government mismanagement of GE foods and crops."

The GM crop, produced by Monsanto Co. (MON) and Dow AgroSciences, was approved 15 days ago by the Canadian Food Inspection Agency.

Christelle Legault, a spokeswoman for the ministry of health, said the modifications present in Smartstax were examined separately between 2002 and 2008 and were regarded as safe.

The CBAN warned the modifications must be tested together to gauge the product's safety.

SmartStax contains two genetic modifications increasing resistance to weed killers and six to protect it from insects.