The owners of the vessel lost contact with it early yesterday while it was in the Gulf of Guinea off the coast of Togo, the IMB's Kuala Lumpur-based piracy reporting centre said in an alert.
"All vessels are requested to keep a sharp lookout for the missing tanker," the centre said.
"Vessels are also advised to maintain a strict anti-piracy watch and measures in these waters."
The Gulf of Guinea, which includes waters off Nigeria, Africa's largest oil producer, has emerged as a new piracy hotspot with 32 incidents so far this year and 62 incidents recorded in 2012 including hijackings, kidnappings and killings.