Trade diplomats said the U.S. stance was set out by Washington's ambassador to the WTO, Rita Hayes, at an informal session of the body's ruling General Council after Canada had proposed an interim agreement on the issue. U.S. officials have been pushing for a pact that would protect products bought and transmitted through cyberspace from the imposition of border customs duties since President Clinton first raised the idea last July. The driving force behind the proposal is known to be Clinton's senior policy development adviser, Ira Magaziner. Hayes first detailed the idea - which would not cover goods ordered over the Internet but then shipped across physical frontiers - to the WTO in February. But, earlier this week, trade negotiators said Washington was now seeking an agreement before a major WTO gathering in Geneva in mid-May, and was indicating Clinton would attend if it could be completed in time for an announcement then. Diplomats said the U.S. ambassador told other envoys at Friday's council meeting that the Canadian idea - which would have WTO countries agree to a standstill until Jan. 1, 2000 - was ``not ambitious enough''. Without directly referring to the May WTO gathering, Magaziner said an accord with no time limit should be reached ``in the next four weeks''. The United States is known to feel such an agreement would give solid weight to the occasion - a WTO ministerial meeting combined with celebrations of the 50th anniversary of the establishment of the post-World War II global trading system. The ministerial meeting, the WTO's highest authority, will be held on May 18 and 20, with the expected summit-level celebrations in between on May 19. The trade ministers, meeting for the second time since the WTO was launched just over three years ago, are likely to issue a declaration confirming commitment to open trade and resistance to any drift toward protectionism. Experts say so-called ``cyber business'' will be one of the biggest growth areas of the global economy in the early 21st century, and point to projections that its value will leap from $8bn (£4.76bn) this year to more than $300bn (£178.60bn) by 2002. U.S. officials argue that its development should not be overshadowed by the prospect of an imposition of tariffs on items like software, architectural plans, audiovisual products or books that can be bought and downloaded over the Internet