The company operates 750 Uniqlo stores in China, its key growth market at a time when it faces slow growth in Japan. China has also been Fast Retailing's crucial production base, with 128 of its 242 global sewing factories located there.

A few items were missing from the Japan launch of its Uniqlo U spring/summer collection last week, raising fears the supply chain disruption in China was beginning to affect business outside the country.

Almost all partner factories have restarted, although not all workers were back at work, the company said on Friday.

"At present, we have secured most of the necessary inventory for our current needs," it added.

Uniqlo's mix of affordable basics and on-trend items has been popular with China's growing middle class, and the company said it remained committed to the market.

"While Uniqlo continues to expand into new markets in such regions as Europe and Asia for example, Greater China (Mainland China, Hong Kong and Taiwan) and Southeast Asia will continue to serve as the key pillars of its business growth," a spokeswoman said in a statement.

(Reporting by Ritsuko Ando; Editing by Shri Navaratnam and Vinay Dwivedi)