Venezuelan oil company PDVSA says it is still working with Bernhard Schulte Shipmanagement (BSM) despite reports the German company is taking crew off 10 managed tankers.

Reuters cited internal PDVSA documents as saying last week that BSM had notified it that it would return operation of 10 of 15 ships it handles for the company.

The oil producer's shipping arm PDV Marina declared a maritime emergency on Thursday due to lack of staff to take over the vessels.

"Our subsidiary PDV Marina continues working with BSM," PDVSA said on Twitter.

"PDV Marina offers maritime transportation of hydrocarbons and tug boat services, reaching satisfactory daily rates."

TradeWinds is still awaiting comment from BSM.

Reuters reported that three other ships operated by BSM for PDVSA remain anchored in Portugal and Curacao until the resolution of legal disputes.

BSM is reported to operate 13 tankers owned by PDVSA and two VLCCs jointly owned by PDVSA and China’s PetroChina.

BSM is said to be owed $15m by PDVSA.