TOKYO, July 20 (Reuters) - Japan's Fast Retailing (9983.T), operator of the Uniqlo casual clothing chain, said its procurement from textile maker Toray Industries (3402.T) would reach 400 billion yen ($4.6 billion) in the five years to 2015.

Uniqlo Kobe Harborland store

That will mark a 70 percent increase from the 240 billion yen in business during the previous five years of their partnership, which has helped Fast Retailing develop hit products and fuelled its global expansion.

Toray supplies Fast Retailing with textiles and has been working with the apparel giant on new fabrics, including the material used in its popular heat-trapping clothing.

Fast Retailing President Tadashi Yanai told a joint news conference he wants to strengthen their partnership as it accelerates a push into overseas markets, where it still gets less than 10 percent of its sales.

"I personally think in some countries we would like to do everything together from production to sales," Yanai said.

(Reporting by Taiga Uranaka; Editing by Michael Watson)