KIEV, June 9 - Ukraine increased reserves of natural gas in its underground storage facilities by 7.3%, or by 857 million cu m, over the past week amid fears that Russian gas supplies may be disrupted on June 10, data released by Gas Storage Europe indicate.

Ukraine accumulated 12.614 Bcm of natural gas as of June 7, compared with 11.757 Bcm of gas it had in the facilities a week ago, according to GSE, a non-profit Brussels-based organization that provides energy statistics to the EU.