Tokyo rubber futures fell more than 1 percent to their lowest level since mid-May on Friday as sharp falls in other commodities such as gold and surging US Treasury yields prompted funds to shift out of rubber.
The key Tokyo Commodity Exchange rubber contract for November delivery fell as low as 273.1 yen a kg the lowest for a benchmark contract since May 15.
Key TOCOM rubber was trading at 273.7 yen, down 1.1 percent from the previous close of 276.8 yen. Technical sentiment weakened after the key contract closed the previous day below the 100-day moving average for the first time since August last year.
The key TOCOM contract has fallen nearly 5 percent since this week's high of 287.0 yen on Tuesday. It is nearly 3 percent below the 100-day moving average of 280.9 yen, with the next key technical support seen at the 200-day average of 252.8 yen.
The key TOCOM gold contract for April 2008 delivery fell about 2 percent in trade. Gold fell on Thursday as the dollar's strength, rising US Treasury yields and a sagging stock market hurt bullion investor sentiment.
China, the world's biggest rubber consumer, has been seeking physical rubber, but the market was not facing tightness as supplies in some parts of Thailand and Malaysia the number-one and number-three producers were improving.
Traders were watching trends in Japanese rubber inventories as TOCOM prices surged last year after domestic stocks dropped sharply during the summer.
The Rubber Trade Association of Japan said on Wednesday that crude rubber stocks held at Japanese warehouses fell 2.7 percent to a four-month low of 17,458 tonnes the lowest since January 31.
The market was watching whether domestic stocks would fall sharply from the current level in the next several weeks.