KIEV, Nov. 21 - Ukraine’s largest oil refinery UkrTatNafta switched to refining crude delivered by oil tankers as Russian oil company Tatneft had continued its supply boycott, a source at the refinery said Wednesday.

UkrTatNafta was operating in emergency mode since October 22 when Tatneft, its minority shareholder and the key supplier of crude, had suddenly suspended the supplies due to a shareholder dispute.

“We started to refine the crude that had been delivered by oil tankers,” the source told Platt’s. “This will keep the refinery busy at least through the end of the month.”