A federal judge today declared unconstitutional the New York-New Jersey Port Authority's ban on permitting the Anglo-French Concorde supersonic jetliner to land at John F. Kennedy International Airport.

Ruling on the narrow issue of federal supremacy over state authorities in granting landing rights, U.S. District Court Judge Milton Pollack said the Port Authority's March, 1976, decision against a 16-month period of test landings at Kennedy was illegal.

Amidst a storm of protests by opponents of the supersonic transport, the Port Authority said immediately that it would appeal the decision.

Simultaneously, Air France and British Airways announced in Paris and London that they intend to begin commercial Concorde flights between those European capitals and New York on June 20.

Those two state-owned airlines are the only ones operating Concordes.

But Pollack ruled that his order will be held up for 10 days while lawyers for both sides agree to the wording of a final judgment. Moreover, an appeal in the federal court system is certain to delay SST landings at Kennedy for months.

Pollack's decision was limited to the grounds that the U.S. government had authority to authorize tests. But if it stands, it could give the nation's airport operators a new club to fight current law that makes them, not the federal government, liable in noise-pollution suits.

If the federal government orders an airport to accept a specific airplane, the airport operators argue, does it not then incur liability for noise suits stemming from the operations of that plane?

Citizens living close to airports are suing in record numbers, and have won some significant settlements.

The ruling had enormous implications for the French and English backers of the Concorde, who view the lucrative Europe-to-New York route as vital to the financial success of their venture.

The Concorde, which cost $3 billion to develop, has been persistently plagued by an inventory of unsold aircraft.

The nine planes operating have been unprofitable, partly because of the relatively small capacity of the planes and partly because existing Concordes are under used because of a lack of routes.

Both French President Valery Giscard d 'Estaing and British Prime Minister James Callaghan have personally exerted pressure on President Carter to intervene in the Concorde dispute, but the President responded that he could not make decisions for New York.

Pollack in his 31-page judgment dismissed as irrelevant other legal claims by the Concorde backers, including arguments that the Port Authority had controverted international agreements. His decision, he said, was based solely on the belief that former Transportation Secretary William T. Coleman Jr.'s order of Feb. 4, 1976, authorizing four SST test landings daily at Kennedy and two at Dulles International Airport at Washington could not be overturned by any state jurisdiction.

"A straightforward question of federal supremacy is raised in this case," Pollack ruled.

Coleman's successor, Brock Adams, yesterday said, "The federal government's position has been consistent that Concorde should be allowed to have a 16-month test at JFK as well as Dulles . . ."

Pollack's decision unleashed a barrage of criticism from scores of Concorde protest groups, covering the spectrum from responsible commentary to sputtering hyperbole laced with threats of massive disobedience.

Gov. Hugh L. Carey deplored the ruling, saying it would "convey to the people who are impacted by this decision the clear impression that the Port Authority . . . is left without power and due process to carry out its important functions."

State Assemblyman Leonard P. Stavisky, a Queens Democrat and one of the most outspoken SST opponents in the legislature, called it an "instrument of great damage to the tranquility of the community."

Carl Berman, a leader of the Emergency Coalition to Stop the SST, said, "We will fight this all the way to the U.S. Supreme Court. I am horrified by this decision."

Bryan Levinson, a lawyer in Howard Beach (adjacent to Kennedy) and head of the umbrealla protest group called Concorde Alert, declared, "The Port Authority has exerted its jurisdiction in New York and New Jersey for 20 years.Now, suddenly, we are told it is powerless."

Levinson said protest groups will begin holding meetings tonight and that some small demonstrations will begin this weekend. "If the Concorde lands at Kennedy, we'll be there to meet it," he said in a telephone interview.

The most vituperative reaction came from Michael Biggio, head of Queens-based Restore Our American Rights (ROAR), a citizens' group that previously has allied itself mainly with militant opposition to integration.

"We're fighting a $3 billion investment, and that's plenty enough money to buy a judge," Biggio said.

He claimed that demonstrations would begin soon that would include efforts to shut down La Guardia Airport, "because that's the Port Authority's weak link. The city can't function without it."

In February, 1976, operations at Kennedy were brought to a virtual standstill by a 2,000-car motorcade in a pouring rainstorm. April 17, a noisy but much more modest motorcade slightly hampered operations at the airport.

Understandably, the reaction from the French and British developers of the Concorde was ebullient.

"We are happy for the opportunity to give the aircraft a fair trial in New York," said Alan Beaves, British Airways business travel manager.

In Paris, Jean Michel Fourtainier, vice chairman of the Committee to Support the Concorde, was more cautious. "It is a positive movement," he said, "but the affiar has not reached its conclusion."