French company Bourbon said three of its crew members were kidnapped from a crew boat off the coast of Nigeria.
The incident happened on the Surfer 1440 after pirates boarded the vessel on April 8.
A spokesman for the company said:”The 3 crew members of Nigerian nationality have been kidnapped. An emergency unit based in Nigeria has been immediately activated.
“Bourbon Interoil Nigeria is in contact with the families, supports and informs them regularly”.
Earlier this month it was revealed three oil workers had been freed after ebing taken hostage in Libya.
Six employees remain unaccounted for.
All of the men are employed by Value Added Oilfield Services (VAOS).
The six workers still being held in captivity include four Filipinos, a Czech and an Austrian.
The men had been kidnapped from the al Ghani oilfield on March 6.