Justice Engoron said then that “the argument that the city is in the state, and so is a state concern, simply proves too much,” adding, “This court has trouble seeing how the provision of taxi service in New York City is a matter that can be wrenched from the hands of city government, where it has resided for some 75 years, and handed over to the state.”

But the Court of Appeals found that the law “addresses a matter of substantial state concern.”

“This is not a purely local issue,” the decision read. “Millions of people from within and without the state visit the city annually. Some of these visitors are disabled, and will undoubtedly benefit from the increase in accessible vehicles in the Manhattan central business district and in the outer boroughs.”

Mr. Yassky said in an interview on Thursday that he expected the yellow-taxi medallion sale to begin in October, more than a year after its uncertain status in the courts threw the city budget into disarray.

Some in the livery industry have expressed concerns about the plan, suggesting that if cars were allowed to pick up passengers, fewer would be available to respond to dispatch calls in lower-traffic areas. One driver interviewed last year mused that the apple green paint was “like a target” for those, like him, who sought to pick up illegal street hails in Manhattan.

And many yellow-taxi operators, disinclined to share street hailing with livery cabs, have challenged the plan since its inception. The Metropolitan Taxicab Board of Trade, a plaintiff in one of the suits, called the decision “a crushing blow to New Yorkers who loathe the brand of end-run politics that created this law.”

“The court’s finding that somehow hailing livery cabs in the Bronx is a ‘matter of substantial state interest’ — code words that were used to bypass the New York City Council — is alarming,” the group said in a statement. “The ruling kicks open the door for systematic abuses for future executives in cities throughout the state, but particularly in New York City.”

The Bloomberg administration received more welcome news on Thursday when an appellate court lifted the injunction against its pilot program to allow taxi-hailing smartphone apps in yellow cabs. The plan, which will allow drivers and riders to find one another without a traditional curbside street hail, has faced intense opposition from livery and black-car operators.