Orica, also the world's biggest maker of industrial explosives, paid KH Foods €8.53m for the flavours and colours firm, operating since the 1930s.
Orica managing director and CEO Malcolm Broomhead said the acquisition is "a further extension of Chemnet's food and fragrance business into new high value product areas that complement Bronson and Jacobs's portfolio."
The publicly-listed firm with €2.3 billion in sales centres around four businesses - mining services, fertilisers (Incitec Pivot), chemicals and consumer products.
From 1 February this year, Keith Harris Flavours and Fragrances will slot into the chemicals branch, under the Chemnet unit.