International NGOs are less transparent than transnational corporations such as the oil giant ExxonMobil and pharmaceutical company Pfizer, according to a report by the research charity One World Trust.
The trust compared 10 NGOs, including Oxfam and WWF, with multinationals such as Wal-Mart and Nestle, over four areas: transparency, participation, evaluation and response to complaints.
It also looked at intergovernmental organisations such as the World Bank.
ActionAid scored the second highest, behind the Global Environmental Facility, both overall and in the transparency category. But NGOs collectively ranked the lowest of all three groups for transparency. They were also found to be the least good at dealing with complaints. However, NGOs were the most successful group at ensuring stakeholder participation.
"Critical accountability gaps in transnational organisations often constrain progress on pressing global problems such as climate change and poverty," said Monica Blagescu, accountability programme manager at the One World Trust. "There is significant room for improvement."
The International Chamber of Commerce ranked lowest among the NGOs for transparency, just below Human Life International. Both scored lower than every corporate. Amnesty International ranked fourth from bottom among NGOs.
World Vision International came top among the NGOs for its complaint and response mechanisms; WWF was sixth in this area. Overall, the World Bank and Pfizer were found to have the best complaints procedures.
Paul Steele, chief operating officer at WWF International, said: "We welcome the study. As an organisation committed to constantly improving our transparency, accountability and public outreach, the report provides a useful independent assessment for our progress in these areas."