NOVI SAD, Yugoslavia (AP) _ A Yugoslav man serving a 15-year prison term for having his American stepmother murdered in New Jersey was released Tuesday after his sentence was successfully appealed, his lawyer said.

Zoran Cveticanin, 29, was convicted by the district court here on April 11 1985. His lawyer, Mitar Radonjic, said the supreme court, which overturned the sentence, had not yet decided on a new one.

The supreme court also granted an appeal by prosecutor Milan Letica to void the acquittal of Cveticanin's sister, Vesna, 26, who was tried on a charge of conspiracy in the murder. However, she was not ordered taken into custody.

The two had been charged in the July 1983 death of 28-year-old Kathryn Denise Cveticanin, the second wife of Vlado Cveticanin, 55. Mrs. Cveticanin was stabbed with a knife in her husband's wicker shop in Glassboro, N.J.

Michael Rose was found guilty of the murder in a New Jersey court and was sentenced to life on Jan. 21, 1985.

The Yugoslav supreme court ordered that records be procured from Rose's trial.

Zoran and Vesna Cveticanin arrived in Yugoslavia in January 1984 after spending 12 years in the United States. They were tried here because the United States has no extradition treaty with Yugoslavia.

Radonjic, the defense lawyer, told The Associated Press the supreme court evidently felt there was no danger the brother and sister would leave the country. Their passports were taken from them upon their arrival in Yugoslavia.

He said that under Yugoslav law, Zoran Cveticanin's original sentence could be confirmed, reduced or suspended, but that because of necessary administrative procedures, once the New Jersey court material arrives, it could be months before a new decision is rendered.