SECRETARY for Trade and Industry Chau Tak-hay yesterday made a veiled criticism of efforts by the United States to introduce the issue of workers' conditions into international trade agreements. Mr Chau, who was speaking at the ministerial conference in Marrakesh, Morocco, to mark the end of seven years of negotiations on the General Agreement on Tariffs and Trade (GATT), warned of ''protectionists hiding behind the worthy motives of others''. Moves by Washington to link trade and working conditions have sparked a bitter response from developing countries who claim that it is a matter of national sovereignty. Mr Chau would not comment directly on the issue but quoted an editorial from the The Economist magazine which concluded that the ''costs of pressing for new links between trade and basic human rights outweigh the likely benefits''. He also said Hong Kong had not signed the Government Procurement Agreement because it breaches the ''fundamental principles of most-favoured nation (MFN) and non-discrimination''. ''We simply could not agree to add Hong Kong's name to such a flawed agreement. We had made a good offer in the negotiations. We have exemplary, open and non-discriminatory systems of public procurement. The agreement was negotiated by 13 countries in parallel to the Uruguay Round. Mr Chau said that the territory was adamant in its support of the MFN principle of equal treatment and ''national treatment'', which required imports to be treated on the same basis as local goods and services. ''Remove these principles and you remove the compass.'' Ministers from more than 120 countries are attending the four-day Morocco conference at which the Uruguay Round agreement is to be signed. Mr Chau said the conclusion of the talks was not an end but a beginning. ''Protectionism is not dead. Barriers to trade still exist. Sin has not suddenly gone out of fashion. Our collective success over the past eight years has been to develop a momentum for change. ''We must work hard to maintain that momentum - lowering trade barriers, scrutinising trade policy, opposing voluntary export restraints and other grey area measures, enforcing the rules we have all agreed upon. ''The World Trade Organisation will be a focus for these efforts. It will have strengthened rules and disciplines to ensure impartial observance by its members of the expanded rights and obligations they have willingly taken upon themselves. ''One new issue to which Hong Kong attaches importance is trade and competition policy. We live in a rapidly globalising economy. The old paradigm based on the assumption that industries and their interests generally speaking have national identities isno longer valid. ''An examination of the relationship between the multilateral trading system and competition policy is needed not only to ensure that multilateral trade rules encourage rather than hinder international competition, but also that the interests of the end-users of the products are duly recognised in a global marketplace. ''Examination of this complex subject will generate considerable heat, requiring as it must a fundamental re-examination of the starting point of competition and trade legislation, including anti-dumping legislation,'' Mr Chau said. In a separate move, ministers from the Asia-Pacific Economic Co-operation forum will be meeting to discuss trade issues at the Morocco summit. An agenda has not been set for their discussions which have been described by an official as being ''informal''. No members of the secretariat will be attending. A spokesman said: ''Their discussions are likely to focus on additional trade liberalisation and trade and investment.''