SINGAPORE: Japanese rubber futures climbed to a 8-1/2-month high on Monday, gaining for a sixth straight session, on firmer oil prices, while heavy rain in top producer Thailand raised concerns over tighter supply.

The Osaka Exchange rubber contract for July delivery finished 3.8 yen, or 1.5%, higher at 257.6 yen ($2.2) per kg, after touching its highest since May 28 of 259.8 yen earlier in the session.

“Rubber futures were well supported by higher oil prices as a result of Russia-Ukraine tensions,” a Singapore-based trader said.

“This morning, there was heavy rain all over rubber plantations in the North-eastern and Southern regions of Thailand, affecting the supply of natural rubber and causing prices to go up,” he added.

Rubber glove manufacturers may be stocking up on raw materials now as they foresee lower output from Thailand in the coming months, with parts of the country entering wintering season, another Singapore-based trader said.

Wintering is when rubber trees temporarily slow latex production while they shed old leaves and grow new ones.

Oil prices on Monday hit their highest in more than seven years on fears that a possible invasion of Ukraine by Russia could trigger US and European sanctions that would disrupt exports from the world’s top producer in an already tight market.

Synthetic rubber is derived from crude oil, and higher oil market serves as a driver for natural rubber prices as well. Natural rubber market also benefits from stronger oil prices as that could lead to a shift from synthetic rubber.

Thai rubber sheet prices hit 71.25 baht ($2.2) per kg on Monday, the highest since June 2021.

The rubber contract on the Shanghai futures exchange for May delivery was down 40 yuan to finish at 14,615 yuan ($2,297.96) per tonne on Monday.