The raid took place on the 1,740-teu Hansa Marburg (built 2007) late on Monday night, 130 miles south-west of Malabo in Equatorial Guinea.
Pirates boarded the vessel and seized two Ukrainians, a Russian and a man from Kiribati.
None of the other 14 men left on board were harmed and L&B is in the process of contacting the families of those involved.
The German owner is also in touch with local and German authorities.
No contact has been received from the kidnappers.
The vessel has proceeded to Senegal.
The attack took place close to where Euronav's 159,000-dwt suezmax Cap Theodora (built 2008) was attacked earlier this month.
