Japan's low-cost clothing chain Fast Retailing - the company behind the Uniqlo brand - plans to open a further 100 shops.

But even as Fast Retailing plans to speed its expansion, fear exists that consumers are tiring of the format.

The move follows 10 straight months of falling same-store sales at Uniqlo shops, a brand that has been compared to Gap .

Uniqlo has become known for cheap, good-quality, casual clothing such as fleeces, with a preference for primary colours, and has won plaudits for its success in a deflationary environment.

Many have tried to imitate its discount format.

Out of the cities

One of its competitors, jeans retailer Right On, has seen its share price double, as some investors hoped that it might benefit from Uniqlo's fading popularity.

In this environment, news of a faster expansion comes as a surprise and Uniquo's share price rose nearly 5% on the news.

The company points out it is closing other shops - about 60 over the next two years - and is now focusing on other parts of Japan, outside of the urban centres like Tokyo and Osaka.

"We don't consider this plan as an aggressive expansion. We consider this plan as neutral and vital to our stable growth," a Fast Retailing spokesman said.

The company opened its first four stores in the UK last year, and plans to open 50 stores within the next three years.

Uniqlo operates 500 stores across Japan.