Unilever, which is part of the Roundtable for Sustainable Palm Oil (RSPO), did not have a contract with Duta Palma, but had been receiving oil from the planter via traders.
Two months ago the consumer goods giant brought an end to a $33m supply contract with Indonesian supplier PT Smart.
Commentators have said the move could make it hard for companies and planters to work together towards greening palm oil supply under the aegis of the RSPO.