UMA is a subsidiary of UMH, a joint venture company, which is in turn jointly controlled by Tarmac Limited (a wholly owned subsidiary of the Anglo American plc Group) and Pioneer Aggregates (UK) Ltd (a wholly-owned subsidiary of Hanson plc).
UMA est une filiale d'UMH, une entreprise commune, elle-même placée sous le contrôle conjoint de Tarmac Limited (une filiale à 100 % du groupe Anglo American plc) et de Pioneer Aggregates (Royaume-Uni) Ltd (une filiale à 100 % de Hanson plc).