UPMARKET fashion retailer Joyce Boutique Holdings will open a 38,000-square foot store in Taiwan in September as part of a regional expansion plan that takes Thailand and China into its sights. The $30 million World of Joyce store will occupy the fifth floor of a giant new retail, office and hotel complex, Far Eastern Plaza, being built in the Ta An district, tipped to become one of Taipei's fastest growing areas. It aims to reproduce the retailing success of the similarly named Joyce store at The Galleria in Hongkong's Nine Queen's Road Central building. However, the Taipei store, which will be 85 per cent-controlled by Joyce, and 15 per cent by Taiwan-based Dynasty Design Corp will be more than twice the size of the Hongkong flagship boutique. It will also incorporate several mini-boutiques selling brand-name fashions represented by Joyce in Hongkong and Taiwan, an art gallery, a child-minding area and a section featuring apparel, accessories and home furnishings made under the Joyce label. ''Our stated strategy for growth comprises both business diversification and geographical expansion,'' said Mr Roberto Dominici, Joyce Boutique's executive vice-president. ''With the recent completion of our group's reorganisation and the successful launch of the World of Joyce lifestyle retailing concept last year, regional expansion of our retail operations will be a priority in 1993.'' Joyce Boutique's share price has been low in recent months as the group's performance has apparently fallen short of expectations of strong growth. A 37 per cent drop in interim profits on a 20 per cent increase in turnover, coming on the heels of disappointing 1992 results, caused the share price to drop to its lowest since listing in 1990. ''Some people have cast doubts on our ability to grow. But short-term results should not make us deviate from our long-term plans. ''Inefficiencies should not prevent us from further investments in an area we strongly believe in,'' said Mr Dominici, who admitted that the company might have portrayed too optimistic a view of the speed and rewards of its internal restructuring. ''We said we would work to contain costs and strengthen management and we have, although it took longer than we would have liked. We also said we would expand regionally and now we're delivering on that promise,'' he said. Mr Dominici called Taiwan ''the next logical step for the group'', citing the country's rapidly increasing annual gross national product per person, currently US$11,000, and its increasing appetite for designer fashions and good-quality merchandise. ''Taiwanese consumers are keenly aware of international lifestyles and fashions and have considerable income at their disposal, yet the market is under-served,'' Mr Dominici said. Joyce expects to open a store of similar scope in Bangkok in 1994 and has targeted China for expansion in 1995. Joyce's Taipei project would be internally financed and was expected to pay for itself in about three years, said Mr Dominici. The group also anticipates additional financial benefit from greater discounts on merchandise orders, which should double because of the Taiwan expansion. ''We'll be able to greatly expand our turnover and buying power without incurring too many additional costs. The management systems already in place in Hongkong can accommodate the expansion,'' said Mr Dominici. The US$400 million Far Eastern Plaza project is owned and managed by Yuan Ding Construction and its parent Far Eastern Textile Group, one of the largest and most diversified companies in Taiwan. Its Far Eastern Department Stores subsidiary, established in 1967, operates 11 chain stores in 10 major cities across the island. Far Eastern Plaza has a building area of 1.8 million sq ft and will include 34 floors of office space and a 425-room luxury hotel managed by Shangri-La International Hotels. The Joyce store will be designed by architectural practice Tsao and McKown, which is designing the US$1.5 billion Suntec City development in Singapore.