Benchmark Tokyo rubber futures shed earlier gains to end lower on Thursday, closing at their lowest in nearly five months, as extended losses in Shanghai futures prompted fresh selling amid worries about oversupply and slowing economy in top buyer China. The Tokyo Commodity Exchange (TOCOM) rubber contract for April delivery finished down 1.9 yen, or 1 percent, at 191.1 yen ($1.69) per kg, the lowest intraday level since Oct. 31, and lowest close since June 26. The most-active rubber contract on the Shanghai futures exchange for January delivery fell 280 yuan to finish at 13,270 yuan ($2,000) per tonne, following the previous day's tumble by 890 yuan.