The benchmark palm oil contract for August delivery on the Bursa Malaysia Derivatives Exchange was last up 1pc at 2,087 ringgit ($497.62) per tonne, heading for a third straight session of gains.
Earlier in the session, it climbed as much as 1.3pc to 2,093 ringgit, its strongest level since May 21.
Palm oil may rise further into a range of 2,089-2,111 ringgit per tonne, said Wang Tao, a Reuters market analyst for commodities and energy technicals.
"The market is tracking strong gains in the overnight soy market," said a Kuala Lumpur-based trader. "The weaker ringgit is also seen as supportive of palm."
The ringgit, palm's currency of trade, eased 0.2pc against the dollar to 4.1940, its weakest level in six months.
A weaker ringgit usually makes the edible oil cheaper for holders of foreign currencies.
In other related oils, the Chicago July soybean oil contract was up 1.3pc on Wednesday, extending gains into a third session.
US grains rose on Wednesday after a US government report showed planting across the Midwest lagging way behind the average pace for the time of year.
Meanwhile, the September soyoil contract on the Dalian Commodity Exchange jumped 2.7pc and the Dalian September palm oil contract rose 2.1pc.
Palm oil prices are affected by movements in soyoil, with which it competes for global market share.