The letter asked the Commission to rescind an order requiring exporters of vegetable oil to use dedicated ships. The letter was signed by Philippine agriculture secretary Salvador Escudero.
The Asean ministers also asked the European Union to reconsider a new trade scheme which uses a country's economic growth data as a guage to determine tariffs on food exports starting January 1, 1997.
Asean groups the Philippines, Indonesia, Malaysia, Brunei, Vietnam, Singapore and Thailand.
Escudero said the European Union had issued a directive in January saying it would allow shipments of vegetable oils only if the vessel transported food items.
Asean, whose members are the world's largest exporters of coconut oil and palm oil, said the directive would make its products less competitive.
If the spirit of the directive is to ensure the safety of foodstuffs during transport, we would like to reiterate that there were no cases of contamination of vegetable oil shipped to the European Union from various sources since October 1993, said Escudero.
Escudero said the introduction of a revised generalised system of preferences for agricultural products from developing countries, including the new Asean dragons, would not only have adverse financial and economic impact on Asean farmers but also political repercussions.