Cetin Dogan and Halil Ibrahim Firtuna, both former generals, and Ozden Ornek, a former admiral, were initially sentenced to life in prison but a court in Silivri Friday reduced the terms to 20 years because the coup attempt had been unsuccessful.
Five retired generals, a retired admiral and the former secretary-general of the National Security Council were sentenced to 18 years each. More than 200 suspects, including retired Col. Dursun Cicek, received 16-year jail terms.
Thirty-four of the 365 officers charged were acquitted in the 2003 coup attempt, known as Sledgehammer, that sought to overthrow the ruling Justice and Development Party of Prime Minister Recep Tayyip Erdogan and the religion-based Gulen movement.
The newspaper Taraf revealed the coup plan in 2010 when a journalist reported he had received a briefcase containing documents outlining plans by members of the Turkish military to destabilize the government by bombing mosques, downing a Turkish fighter jet, taking over hospitals and pharmacies, closing non-governmental organizations, and arresting journalists and politicians.
The defendants claimed the evidence was fabricated.
Turkey's military staged three coups between 1960 and 1980.