Eight construction firms have offered financial settlements to workers who said they were blacklisted within the industry.
The GMB and Ucatt unions and a law firm representing claimants have also accepted an apology.
The case emerged in 2009 following a raid on the Consulting Association in Droitwich by the Information Commissioner's office.
It uncovered a list of more than 3,000 names and reference cards.
They detailed workers' political views, competence, trade union membership and industrial relations activities.
The defendants in the case are Balfour Beatty, Carillion, Costain, Keir, Lang O'Rourke, Sir Robert McAlpine, Skanska and Vinci.
In a submission to the High Court last year, the firms accepted that construction companies had provided much of the information and had used it to vet workers seeking employment.
The companies accepted that the vetting information system "infringed workers' rights to confidentiality, privacy, reputation and latterly data protection".
The companies offered an "unreserved apology" for their part in operating the system, for any adverse employment consequences and for the distress and anxiety caused to workers and their families.
Despite the admissions, the firms continued to defend cases where they claimed there was no link between the vetting system and the loss of employment and where the losses being claimed were unsubstantiated.
The case had been due to be heard at the High Court next month.
In a statement the firms said: "In October 2015, these construction companies, unlike any other companies involved in the vetting system, openly acknowledged that the system was unlawful in various respects and made a full public apology, which was widely reported at the time.
"The construction companies have offered financial settlements which all claimants represented by Ucatt, GMB and [law firm] GCR have now accepted as fair and reasonable. The parties have also agreed a joint statement to be read in court as part of this settlement. These construction companies now wish to draw a line under this matter."
There is outstanding litigation between the construction companies and the Unite union, with a trial due to start on 9 May.