Busic will not be released by the end of this month and then deported to Croatia as announced in mid-September, Vecernji List daily said citing the management of Allenwood prison in Pennsylvania, where Busic is serving his sentence.
A court committee processing prisoners' requests for parole has postponed a decision on Busic's case until July 2008, said the newspaper.
Croatian media last month said Busic would be paroled and deported to Croatia, and the United States Embassy Zagreb confirmed on that occasion that Busic had been transferred to the deportation prison of the US Department of Homeland Security, where he was to have waited until the deportation procedure was cleared.
According to the US Department of Justice, a group of Croatian political activists led by Busic hijacked a civilian plane en route from New York to Chicago on 10 September 1976, intending to use it to drop over London and Paris leaflets which explained the situation in the then Croatia and called for its independence from Socialist Yugoslavia.
The plane landed in Paris, where the hijackers surrendered after those leaflets were published in the US print media at their request.
Before boarding the plane, the hijackers left a bomb in a New York subway locker, conveying this information via the pilot. A US police officer was killed while deactivating the bomb.
Under US law, Busic was sentenced to lifetime imprisonment for hijacking and an act which led to the death of another person, with the possibility of parole after 10 years. That sentence envisaged release after serving 30 years in jail, specifically 11 September 2006.
Also convicted were his wife Julienne Eden Busic and another three Croats, all of which have served their sentences.