Shipments of oil products from a Russian Black Sea outlet have been disrupted since early February due to a row over the port's control, four industry sources told Reuters on Wednesday.
Three sources said oil products shipments from the IPP terminal at the port of Novorossiisk have been delayed over a managerial conflict.
The port did not reply to a written request for comment.
According to the sources, between 1,000 and 2,500 rail cars with oil products are stuck near the port waiting to be loaded on to tankers.
Trading sources also said that loading operations of two tankers - Andromeda, chartered by Litasco, and Trafigura's Atlantas II - have been cancelled.
"Ships have been waiting in the harbour of Novorossiisk," a trader said.
It is not clear when the port will return to normal operations. Each month it handles around 300,000 to 350,000 tonnes of oil products, mainly naphtha and diesel.
Reporting by Gleb Gorodyankin in London and Natalia Chumakova