The Post Office, HKPS and its allied organisations, the Hong Kong Stamp and Coin Dealers' Association and the Hong Kong Tourist Association, have come together to set up the secretariat for the expo.

Joanna Choi, secretary-general of the organising committee and a senior controller of posts, was seconded from the Post Office. She has been assisted by Y. F. Chan, the Controller of Posts, and support staff.

Ms Choi said: ''The exhibition is the culmination of the efforts of local philatelists and the Hong Kong Government.

''Local philatelists, as keen stamp collectors themselves, have always hoped to organise a large show in Hong Kong to promote philately.

''The Government and the Post Office, in particular, wanted to generate interest among the youth in Hong Kong in this healthy and worthwhile hobby.'' The exhibition is funded almost exclusively by the Government, which has allocated $13.5 million.

''This is just about enough to meet all the expenses for an event of this scale, where philatelists from around the world and many overseas postal administrations will be taking part,'' Ms Choi said.

''To complement the funds allotted by the government, we have got some advertisements and secured corporate sponsorships; like the one from Cathay Pacific, which is the official carrier for the event (the airline is sponsoring the tickets for the overseas jurors); the Hongkong Bank, which is the official banker; and Central Plaza, which is Asia's tallest building and is incorporated in our logo.

''The jurors for the exhibition are all experienced stamp collectors who have won many international prizes for their collections. They have been selected by the Federation of Inter Asian Philately (FIAP).'' The exhibition will bring to Hong Kong many valuable collections: about 400 frames of invited and competitive exhibits will be on display.

Frames from China, Taiwan, Macau and Hong Kong will be on show in a competition at the expo. Commissioners from these four regions will be co-ordinating entries from within their jurisdictions.

The international jurors will award eight gold medals: Large Gold Medal, Gold Medal, Large Vermeil Medal, Vermeil Medal, Large Silver Medal, Silver Medal, Silver Bronze Medal and Bronze Medal.

''For a philatelist, it is an honour to get awards and recognition because then it enables them to participate in more and more prestigious exhibitions,'' Ms Choi said.

''For both philatelists and the lay public these exhibitions afford a chance to see extremely good stamp collections - only on these occasions do philatelists bring and display their prized possessions.

''The objective of the Hong Kong Government is to provide an international forum for philatelists from all over the world to come together under one roof and hold discussions.

''At the exhibition, there will be seminars on special subjects related to philately.

''Through stamps, people can learn about the history, geography and culture of people from different countries.'' Activities at the expo will include a youth corner where seminars will be held for school children.

Opening hours for the Hong Kong Stamp Exhibition: Today: noon to 7 pm.

Tomorrow: 10 am to 7 pm.

Sunday: 10 am to 7 pm.

Monday: 10 am to 4 pm.

Experts will explain the techniques of collecting stamps, mounting them, and how stamps are printed.

An attractive starter kit to induce children to take up the hobby will be distributed.

A ''Philatelic Passport'', which includes specially cancelled stamps of more than 80 participating postal administrations from overseas, has also been produced for the expo.

This $280 souvenir has stamps from places such as the Ascension Islands, which as a population of 1,099; the first issue from the former Yugoslav state of Croatia, which issued its first stamp in 1991; and other distant lands.