The subsidiary, which provides litigation support services to the legal industry does not provide any print services, but Datalex's customer base of big European law firms will complement its UK and US users.
Terry Harrison, managing director at Hobs Legal Docs, said: "There is a great synergy between our two companies as we are both young, dynamic and share a total commitment to delivering high quality services to all our clients.
"Bringing us together will add further experience, skills, solutions and capacity to our customers as well as enhancing our overall service offering, the most imminent of which is in the area of data forensics and collections."
Demetriou will join HLD as a director.