Veteran journalists and writers Nazli Ilicak and the brothers Mehmet and Ahmet Altan were handed the life sentences at a trial in Istanbul over alleged connections to the outlawed group of US-based preacher Fethullah Gulen, the Anadolu news agency said.
Similar sentences were given to three other suspects.
They were all convicted of seeking to usurp the constitutional order in Turkey.
Gulen, who built up substantial influence in Turkey through media, education and banking interests before falling out with the authorities in 2013, denies having links to the coup bid.
The ruling came as Turkey freed German-Turkish journalist Deniz Yucel, the correspondent of the Die Welt daily, who had been held for more than a year without charge in a separate case.
According to the P24 press freedom group, there are 156 jailed journalists in Turkey, most of whom were held in the mass crackdown after the failed coup aimed at ousting Erdogan.
– ‘Disregard for the rule of law’ –
Speaking in Ankara hours before the verdict was delivered, the head of a top European rights watchdog expressed concern over the arrests of journalists, MPs, mayors and activists since the coup.
“The result of casting the net too widely is to spread a chilling effect across society as a whole,” said Council of Europe chief Thorbjorn Jagland.
Ilicak, 73, was one of the very first journalists arrested in July after the coup bid. Briefly an MP from 1999, she wrote for several dailies including Hurriyet.
Ahmet Altan, 67, is a novelist and journalist who has written for some of Turkey’s leading dailies including Hurriyet and Milliyet. He founded the now closed opposition daily Taraf.
Mehmet Altan, 65, has written books on Turkish politics. Both were detained in early September although Ahmet Altan was released in mid-September before rapidly being re-arrested.
In the same case, the court gave life sentences to former Zaman newspaper marketing manager Yakup Simsek, police academy instructor Sukru Tugrul Ozsengul and Zaman layout designer Fevzi Yazici.
The Altan brothers and Ilicak are also accused of appearing together on a TV show on a pro-Gulen channel just before the coup bid and issuing a message that the attempted overthrow was in the offing.
The International Press Institute (IPI) said it was “appalled” at the verdict, describing it as in “utter disregard for the rule of law”.
– ‘Decisions are binding’ –
Mehmet Altan was in January ordered to be freed by the Constitutional Court but the ruling was not implemented by the criminal court in a move that outraged supporters.
The failure to release Mehmet Altan and fellow writer Sahin Alpay — who is being tried in a separate case — raised new alarm over the rule of law in Turkey.
The Ankara-based Constitutional Court had ruled that Mehmet Altan and Alpay should be freed on the grounds that their rights had been violated.
But Istanbul criminal courts refused to implement the order, saying it had not been properly communicated in a move that raised fears of political interference.
Jagland praised the Constitutional Court’s ruling and warned: “These decisions are binding. This is guaranteed by the Turkish Constitution. Other courts must abide by them.
“If the decisions of the Constitutional Court are not implemented, the rule of law will be undermined.”
In another prominent process seen as a test case for press freedoms, 17 current and former writers, cartoonists and executives from the opposition Cumhuriyet (“Republic”) daily remain on trial on charges of supporting terror groups.
Three of the suspects are still behind bars, including investigative reporter Ahmet Sik. The next hearing in that case is on March 9.