Swinburne University's fifth National Science and Technology Monitor has found most people well informed about GM but mistrustful of the institutions that commercialise GM foods.

Swinburne's survey asked 1000 respondents how comfortable the were with GM plants for food and the latest average score was 3.9 on a scale of 10 where zero is 'not at all comfortable'.

Gene Ethics director Bob Phelps said a lot of the mistrust came from the public's perception of Monsanto, which owns more than 90 per cent of commercial GM soy, corn, canola and cotton lines.

"Monsanto's management and shareholders should be ashamed of ranking absolutely last among the 541 trans-national companies assessed by the annual Geneva-based Covalence reputation index," he said.

Covalence's Ethical Quote score and rankings reflect the historical evolution of the positive and negative aspects of each of the 541 multinational companies' ethical reputations.