THE mood was merry but understandably subdued as Hong Kong's pioneers of trade in Vietnam gathered to toast the lifting of the US economic embargo. Instead of champagne, there was wine, beer and sighs of relief. Participants could be excused for feeling the celebration was slightly anti-climactic. Given the planning - two decades by many counts - this was a coming out party that should have been held long ago. ''I'm really excited, but also tired. It's been a busy week,'' said Penelope Post, executive director of the Vietnam Business Association of Hong Kong. Her office has been deluged with calls since the end to the embargo was announced. ''There's even more work ahead,'' said Ms Post. ''But this is a really good thing. This will be good for Vietnam and good for people doing business there. For so long, there was this roadblock. Now, it's an open field and things are bound to move forward.'' For Hong Kong native Melinda Butts, the timing could not have been better. A holiday in Vietnam resulted in a job offer from New World, which plans to open the country's largest joint venture hotel, the 550-room New World Saigon, in July. Ms Butts started as marketing service manager last month. ''It's wonderful; things will really take off for Vietnam. It's the country with the most exciting prospects both for business and leisure in Asia. And I'm going to be there,'' she said. Nor will she be without company from Hong Kong. Ms Post said the Vietnam Business Association began as little more than a breakfast club three years ago. ''In the beginning, we just got together informally to exchange stories, you know, information on how to get visas and where to stay.'' However, the association has grown to a paid membership of 250, with numerous projects in Vietnam. Ms Post estimated that at least 25 per cent of the members were US companies or entrepreneurs. ''They're ready,'' she said. ''The Americans have been lined up and waiting to go.''