Judges ruled it would not be in the interests of justice for Dermot James Wade and Dennis Patrick McAlmont to go before a jury again.
Reporting restrictions were also lifted to allow identification of the pair, who are cousins.
Following the ruling Mr Wade, 50, spoke of his relief that his "ordeal" was over.
The retired builder said: "It's been a nightmare for the last nine years for me and my family."
Mr Wade and Mr McAlmont, 48, were jailed after being convicted in 2004 of a series of charges including indecent assault, gross indecency and buggery.
The alleged offences spanned more than 20 years, from 1973 to 1995, with the defendants accused of beginning the abuse in their teens.
Charges were brought against them after police received a complaint and launched an investigation in 2002.
Although a defence was put forward that the allegations were deliberately concocted to obtain money, a jury sitting at Antrim Crown Court found them guilty.
They appealed the verdict on a number of grounds, including insufficient directions being given to jurors deciding an historic sex abuse case.
In quashing the convictions the Court of Appeal held that summing up on the passage of time during the trial was not balanced between complainants and defendants.
A panel of three senior judges, who then sat on Friday to decide whether to order a retrial, were told three witnesses were prepared to give evidence again, but another three were not.
A Crown lawyer said it was unlikely that the prosecution would seek to compel the more reluctant ones.
Frank O'Donoghue QC, appearing for Mr Wade and Mr McAlmont, told the court both men had served the equivalent of a nine years six months prison sentence.
He argued that under normal remission rules the pair would by now have been released.
"It would be against the interests of justice to retry either of these appellants," Mr O'Donoghue said.
"The factual matrix has altered, given the passage of time and the fact these men have spent such a considerable time in prison and their sentence are effectively concluded."
Ruling that a retrial should not be ordered, Lord Justice Higgins pointed out that it would have only been in relation to counts where a maximum two year sentence could be imposed.
The judge said: "It is clear that the nature of the trial which would proceed would be a very different trial from the one that proceeded in 2004.
"Both Mr McAlmont and Mr Wade were sentenced to long terms of imprisonment. They have served substantial proportions of those terms of imprisonment."
He added: "We do not consider in all the circumstances that the interests of justice would be served by their being a retrial in this case."
Outside the court their solicitor, John Greer of Reavey and Company, said he was delighted to have acted for both men.
Mr Greer also said: "This case identifies and highlights the dangers associated with historic allegations of sexual abuse, and the very real difficulties that defendants encounter when defending the cases and bringing appeals."