Two brothers have been sentenced to a total of 76 years in prison by an Australian court for planning to blow up an Etihad Airways flight from Sydney to Abu Dhabi with a bomb hidden in a meat grinder.

The New South Wales Supreme Court on Tuesday sentenced Khaled Khayat to 40 years in prison with no parole until 2047. His brother, Mahmoud Khayat, was sentenced to 36 years with no possibility of parole until 2044.

The two men had been found guilty of planning two terrorist attacks: the bomb and a chemical gas attack on the flight to Abu Dhabi in July 2017.

Khaled was found guilty by the New South Wales Supreme Court in May, but the jury was unable to reach a verdict against Mahmoud. His retrial also ended with a guilty verdict in September.

Khaled and Mahmoud Khayat were arrested after police raids in Sydney.

Police had said that high-grade explosives used to make the bomb were flown from Turkey as part of a plot "inspired and directed" by the Islamic State.

The improvised device was to be smuggled inside the luggage of a third, unwitting brother.

A fourth brother, who is said to have fought with the Islamic State in Syria, is accused of directing the plot from overseas.