WHEN officials representing the Buildings Ordinance office and the six supporters of the International Building and Construction Expo (IBEX) cut the ribbon at 10 am today, they will be launching the 10th and largest IBEX yet. This year the show will host 526 companies from 31 countries. This exceeds last year's turnout by almost 50 per cent, and emphasises the prime importance of IBEX as a regional show. The large turnout also reflects the remarkable amount of construction taking place in Hongkong and China. The airport project is the major attraction but the Hongkong Government's commitment to building public housing and the successful land auctions during the past months all form part of a major market for a range of building industry products. The double-digit growth in the Pearl River Delta linked with the large number of infrastructure and development projects planned in many other parts of China is an additional magnet to overseas companies looking for a slice of the action. The products on display should meet the most critical tastes. Ceramic floor files from Australia and Spain, tempered glass from Singapore, marble furniture from the Philippines and automatic doors from Japan give some idea of the range of products that will be on display. If you want to find artificial grass or surface water drainage systems, locking systems or building management systems, IBEX is the place to go. ''We are expecting the show to be more successful this year because of its increased size,'' said Patrick Leung, general manager of Reeds Exhibition Companies. ''This is partly due to the 3rd World Plumbing Congress, which has more than 1,200 delegates. ''The economy of southern China has picked up rapidly and with Hongkong at the doorway to southern China we should benefit.'' Mr Leung said because his company also organised a similar event on alternate years in Beijing and Shanghai, fewer people had visited IBEX from the northern part of China. But this year a delegation of 50 building professionals from Shanghai were invited. They will be sourcing a variety of equipment for projects on the mainland. Mr Leung said he was happy to see the show grow with the market and he expected IBEX to become more important in the future. If China maintains its open door policy then we expect the show to continue to play a major role,'' he said. More than 12,000 visitors made up of architects, engineers, interior designers, and decorators from Hongkong and the world are expected to attend this year's exhibition. A survey conducted at the show last year indicated 57 per cent of visitors were decision-makers who could either recommend or authorise buying goods. More than 80 per cent of those polled indicated their choices were influenced by what they saw at the exhibition. In a new venture, this year's show is being held in conjunction with the Third World Plumbing Congress. ''The Plumbing Congress and IBEX are two separate events but by bringing these two big events together we hope to arouse more interest,'' Mr Leung said. ''It will also help the visitors, who can now come to Hongkong and attend two events at the same time.'' In addition to the plumbing congress, the scope of the exhibitors was changing. Mr Leung said for the first time some machinery exhibitors were taking part. A company representing a Japanese excavator manufacturer will be promoting its products. IBEX is supported by the Chartered Institute of Building, the Hongkong Institute of Architects, the Hongkong Construction Association, the Hongkong Institution of Engineers, the Institute of Clerks of Works and the World Plumbing Council (Hongkong). Admission to IBEX, which will be held at the Convention and Exhibition Centre from today until June 19, is open to trade only. Opening hours are from 11 am to 7 pm daily.