The 12,800-dwt Fair Artemis (built 2008) was 60 miles off the coast with a 24-strong crew and a cargo of gasoil at the time when it last made contact on Wednesday.
Greece's Fairdeal Group told TradeWinds it has been trying to re-establish contact.
The company criticised alarmist reports from the IMB and said no one yet knew what had befallen the vessel.
It added Ghana had pledged to send helicopters out to search for Fair Artemis.
Fairdeal fleet director John Gray said: "Our primary concern at this time is for the safety of those on board the vessel. We would like to assure their families and all stakeholders that we are fully committed to returning the crew and vessel to a safe port."
Vessels in the area are being contacted to provide any further information.
The company's local agents are closely coordinating with the Ghanaian coast guard. Navy ships are also likely to be deployed.
