The man was given a life sentence in 1990 for a 1985 attack in the Danish capital. He and two other Palestinians planted two bombs - one outside the offices of American airline Northwest Orient and another outside the city's synagogue. One person was killed at the airline office. The man was convicted of murder, although lawyers say that today he would have been convicted under terror crimes legislation.
The year after he was convicted the man escaped from Kumla jail, but was later returned to custody.
The record sentence reflects a wish by the Örebro District Court not to release the man immediately, argues criminal law expert Dr.Josef Zila.
"He has been in jail for about 18 years and if the time limit had been set lower than thirty years they would have been obliged to release him immediately.
"Now, under the rules stipulating release after serving two thirds of a sentence, he will be let out after serving 20 years - in other words in 1.5 years," said Zila.
Zila said that he and most other criminal law experts wanted life sentences abolished and replaced with a graduated scale for murder sentences, starting at ten years and ending at 30 years.
The man's lawyer said his client was likely to react positively to the court's verdict.
"I haven't had time to talk to my client yet, but I think that he'll be pleased to finally have a time limit on his sentence. Planning for his release can now begin," the lawyer said.