Mahathir, speaking during a state visit to Indonesia, said the neighbours faced "similar problems" in the industry.
"Our palm oil is threatened by Europe and we need to oppose them together," Mahathir told a joint news conference with Indonesian President Joko Widodo.
The European Union is among the two countries' largest export markets for palm oil, but it has moved to curb its use to meet climate goals.
Palm oil is used in a wide range of products from chocolate to shampoo and the industry has come under scrutiny in recent years as it is often blamed for causing deforestation and forest fires.
"European countries used to be covered with forests but they've cut them down and nobody argues with them about it. But when we clear land they say it pollutes the climate," said the 92-year-old premier, who recently came back to power in Malaysia after a shock election victory.
Mahathir also said the neighbours had revived plans to jointly develop a car to be sold in Southeast Asia.
In Japan earlier this month, Mahathir had said he hoped to begin a new car project to follow Proton, the car company founded during his first premiership stint in 1983.
Initially floated years ago, the so-called the "ASEAN car" was to be developed by Proton and Indonesia's PT Adiperkasa but the project was shelved.
"In 2015 we could not proceed because of certain reasons but now we plan to continue this project again," Mahathir said, without elaborating.
Proton has struggled in recent years, and last year saw Chinese auto company Geely taking a 49.9 percent stake in the carmaker.
Reporter: ANTARA
Editor: Ade P Marboen
Copyright © ANTARA 2018
