Altan faces several charges, including an "attempt to overthrow the government of Turkey and prevent its function, and being a member of a terrorist organisation", state-run news agency Anadolou said.
Turkish and international groups have called for Altan's release.
Altan's brother, a prominent Turkish journalist, Ahmet Altan, was freed on Thursday under "judicial control", according to the press reports.
The Altan brothers were detained for questioning on September 10, accused of sending "subliminal messages" suggesting a military coup when they appeared on a TV show on the Can Erzincan channel a day before the failed July 15 putsch.
Writers, musicians and artists from around the world, including three Nobel laureates have urged Turkey to release the Altans.
The Can Erzincan channel has now been shut down along with dozens of other media outlets deemed to be associated Fethullah Gulen, the US-based cleric who Turkey accuses of orchestrating the attempted coup, which was swiftly crushed by Turkey.
A total of 260 people were killed in the failed coup bid and more than 100 left-wing journalists have since been arrested, along with tens of thousands of police, soldiers, judges and civil servants amid a widening probe of Gulen and his alleged supporters.
Gulen, who lives in self-imposed exile in the US, had built up a substantial media presence in Turkey. Most of his outlets have been closed since the coup. He denies all of Turkey's accusations.
