A joint holding company to be formed April 1 by Honen Corp. and Ajinomoto Oil Mills Co. will merge with another cooking oil producer, Yoshihara Oil Mill Ltd., to create the largest domestic entity in the field, according to the three firms.

The planned holding firm, Honen Ajinomoto Oil Mills Inc., will combine with Yoshihara Oil on April 1, 2003, because the firms have found it necessary to increase their international competitiveness in the maturing cooking-oil market, they said Tuesday.

The joint holding firm will be renamed when Yoshihara Oil joins, but the name has not yet been decided.