In March, Unilever said it planned to convert the 1999 Dutch cumulative preference shares into ordinary stock, but some holders said the company had given the impression in the past that it would buy them back for 6.58 euros per share.
Analysts have estimated that a cash payment could cost Unilever about 1.4 billion euros ($1.9 billion), while its planned share conversion was worth 1 billion.
Unilever has previously said it was "fully co-operating" with the court.