The company did not elaborate beyond a red banner at the top of its website on Thursday: "OceanGate has suspended all exploration and commercial operations."
It had planned two expeditions to the century-old Titanic ruins, located in a remote corner of the North Atlantic, for June 2024, its website showed.
US and Canadian authorities are investigating the cause of the undersea implosion last month, which killed all five people aboard and raised questions about the unregulated nature of such expeditions.
The US Coast Guard last week recovered presumed human remains and debris from the submersible, known as the Titan, after searching the ocean floor.
Examination of the debris is expected to shed more light on the cause of the implosion.
The Titan lost contact with its support vessel during its descent on June 18. Its remains were found four days later, littering the seabed about 488 metres from the bow of the Titanic wreck.
