Japanese department store chain Sogo & Seibu says it has no plans to fire staff or close outlets under the management of a US investment fund.

The major chain was sold to Fortress Investment Group in September last year. The company unveiled a management plan on Thursday.

Under the plan, the firm will reduce the floor space by about half at its flagship store in Tokyo's Ikebukuro district. The outlet is being renovated and will focus mainly on luxury goods, cosmetics and food when it reopens next year.

The company says it will reduce costs at its other nine outlets in Japan, but has no plan to close stores.

Sogo & Seibu employees took to the streets in August last year to protest the sale. It was the first labor strike at a Japanese department store in 61 years.

Sogo & Seibu representative director Jin Ryu said the chain will maintain its current staff numbers, even after downsizing the Ikebukuro store.