Former mayor Hugh J. Addonizio of Newark, N.J., may be re-imprisoned on 64 extortion and conspiracy charges as a result of an unanimiousSupreme Court ruling yesterday.

He was released in 1977 after serving five years of a 10-year sentence. Whether he will serve more time-possible 2 1/2 to 3 years-will be determined by the U.S. parole commission.

The commission also will determine whether former Jersey City mayor Thomas J. Whelan and former city councilman Thomas M. Flaherty will be reincarcerated on their corruption convictions.

They and Addonizio, who was elected to two terms as Newark's mayor after 14 years as a democratic congressman, were freed by a ruling of the 3rd U.S. Circuit Court of Appeals.

The key issue in all the cases was whether the duration of imprisonment intended by the sentencing judge prevails over a change in parole commission policies made after sentences were imposed. The 3rd Circuit said the judge's "sentencing expectation" controlled, but it was reversed yesterday, 7 to 3. Justices William J. Brennan Jr. and Lewis F. Powell Jr. did not participate.

In the Addonizio case, U.S. District Court Judge George H. Barlow, in imposing sentence, didn't comtemplate that the commission would reply on the seriousness of the offense as a reason to deny the former mayor the parole he otherwise would received after serving 3 1/2 to 4 years.

But the commission practice in effect at the time was later changed to make the gravity of the offense a significant factor. As a result, the commission twice refused to grant parole to Addonizio after he became eligible in July 1975.

He then sued, won and was released, not merely paroled.

In the opinion for the Supreme Court, JusticeJohn Paul Stevens wrote that the federal criminal code doesn't support the "collateral" attack on the original sentences made by the three former New Jersey officials.

The court handed down other decisions.

By a 5-to-4 vote, the court upheld a New York state law under which the presence of a firearm in an automobile allows the presumption that it is illegally possessed by everyone in the car.

As applied to the particular case, the presumption is "entirely rational," Justice Stevens wrote for the majority. But for the four dissenters, Justice Powell said "the court seems to presumptions that could seriously jeopardize a defendant's right to a fair trial."

Powell's dissent was signed by Justice Brennan, Potter Stewart and Thurgood Marshall. The ruling reversed the 2nd U.S. Circuit Court of Appeals.

The case dates of 1973, when a policeman stopped a car for speeding. The occupants were three men and "Jane Doe," 16. Through a window, he saw in her open handbag two large-caliber handguns. In the trunk he found a pound of heroin and a machinegun. All the weapons were loaded.

A jury convicted all four occupants of possession of the handguns but acquitted them of possession of the machinegun and the heroin. Six separate attacks, in various state and federal courts, then were made on the constitutionality of the state's reliance on the presumption in the absence of evidence otherwise sufficient of conviction.

When the 2nd Circuit found the presumption arbitrary and invalid on its face, Stevens wrote, it contemplated its fairness entirely in "hypothetical situations . . . in which it is improbable that a jury would return a conviction . . ."

Powell protested that the majority was allowing the "plainly irrational" inference that each occupant possessed the handguns to be drawn from the mere presence of the firearms in the car.

In other rulings, the court:

Held 8 to 0 that the first amendment isn't violated by a 1927 Washington law requiring each major political party to have a state committee consisting of two persons from each county in the state.

Rejected, also 8 to 0, a Justice Department contention that an interview in a private attorney's office at which a sworn statement is made constitutes, under the Omnibus Crime Control Act of 1968, "a proceeding ancillary to a court or grand jury."