The tenders close on May 18, they said.
The TMO will hold 15 separate tenders each for 12,000 tonnes of corn, with Russia not named as an accepted origin, traders said.
Turkey has in the past been a major importer of Russian corn. But the sudden end of duty free status in March effectively stopped Turkish imports of Russian wheat, corn and sunflower oil in a move suspected to be related to a wider trade dispute.
Turkey resumed wheat and sunflower oil imports from Russia on Monday but the status of corn imports is still unclear.
The TMO is seeking corn sourced only from the European Union, Moldova, Bosnia Herzegovina, Serbia, Albania, Belarus, Ukraine, Kazakhstan, Georgia, Canada, United States, Argentina, Brazil, South Africa or Australia.
But ship loading can only be undertaken at ports in the Black Sea, Aegean Sea and Mediterranean which effectively limits the possible suppliers to countries close to these seas, traders said.
Offers are sought in Turkish lira.
The TMO also purchased about 44,000 tonnes of corn to be sourced from the European Union and Moldova in a previous tender on April 25.