UDR man James Speer, who was from Desertmartin, was working in his car repair business in November 1976 when he was shot by an IRA gang.
Matt Jury is one of the legal team that spearheaded the successful civil action against four members of the RIRA for the 1998 Omagh bombing.
He told the News Letter: “We can confirm that a writ has been served by the Speer family, and that any ensuing proceedings will follow their ordinary course.”
A solicitor acting for Mr Milne told the News Letter: “Our client strongly denies the allegations made by the plaintiffs to this action and will robustly defend these proceedings.
“Given that these proceedings are ongoing it would be inappropriate to comment any further.”
In October Mr Speer’s daughter Deirdre told the News Letter that her father’s business was only a few feet from their home when he was murdered.
“I was 16. My sister Cheryl was 14 and my brother Dermot was 10. It was coming up to my 17th birthday,” she said.
They all heard the shots. Her father’s secretary phoned across to their mother “and we all ran out and we saw him taking his last breaths. I saw him.
“It is not something that ever leaves you. It is something you never forget - the sight of his dead body lying there, all the blood.”