SHANGHAI, Jul 1 (SMM) - The price ratio has been narrowed recently due to the falling overseas nickel prices and the rising premiums of US dollars in the bonded zone. According to SMM research, the bonded zone inventory stood at 7,700 mt this week, flat from the previous week. The inventory of nickel briquette was 2,900 mt, and that of nickel plate was 4,800 mt. Bonded zone inventory stayed unchanged this week as the downstream demand of pure nickel remained weak and some overseas pure nickel had yet to arrive at ports.