A federal judge ruled Wednesday that New York City police unions will not be permitted to intervene and try to keep alive an appeal of a landmark ruling ordering the NYPD to reform its stop-and-frisk practices.

The ruling by U.S. District Judge Analisa Torres in Manhattan could pave the way for finalizing a settlement between the plaintiffs and the new administration of Mayor Bill de Blasio, who agreed to stop appeals and begin implementing the court-ordered reforms.

But the Patrolmen's Benevolent Association, one of the key unions fighting reforms, said Wednesday it plans to appeal, which could further postpone the start of talks between the city and plaintiffs on how to change training, discipline and supervision.

"The proposed settlement of the case will substantially impact New York City police officers," said PBA President Patrick Lynch. "It is unfair and inconceivable that employees would not be allowed in this process."

U.S. District Judge Shira Scheindlin ruled last year that the city had turned a blind eye to stop-and-frisk practices that were unconstitutional and racially discriminatory. She named a monitor to oversee discussions on ways to reform and ordered a pilot program to use cameras to film stops in some precincts.

The Bloomberg administration denounced the ruling and appealed, and the 2nd U.S. Circuit Court of Appeals ordered a stay in implementing her decision and removed the judge from the case for an appearance of bias. But when de Blasio took over, his administration quickly agreed to withdraw the appeal and follow the decision.

Torres, who took over the case from Scheindlin, said police unions had no standing to contest the city's decision to settle a lawsuit against the city.

"The unions' contention that all NYPD officers are besmirched by the liability order rests on the flawed assumption that anonymous officers who have not taken part in this litigation have a reputational interest arising from the court's finding against their employer," Torres wrote.

Torres also approved a change in Scheindlin's order that was requested by the city and the plaintiffs, limiting the term of the court monitor to three years as long as the city shows during that time that it is making substantial progress in implementing reforms.

Discussions on reforms have been on hold because the 2nd Circuit stayed implementation of Scheindlin's decision while the unions' right to keep the city appeal alive was litigated.

Plaintiffs said Wednesday they were worried that the unions' decision to appeal Torres' ruling could produce more delay if the 2nd Circuit agrees to reconsider their objections.

"It's very disappointing to hear that the unions want to continue a 15-year fight in court as opposed to sitting down and coming up with a solution together, which is what the court-ordered remedial process is designed to do," said Darius Charney, a lawyer with the Center for Constitutional Rights.

The city had no immediate comment.