Russian oil pipeline monopoly Transneft said on April 4 it had stopped taking oil from a unit of Rosneft due to the oil’s low quality, but the subsidiary said it had halted the supplies due to pre-commissioning work at its oilfield.

The subsidiary—Taas-Yuriakh, located in east Siberia—supplies oil to the East Siberia Pacific Ocean pipeline as part of the ESPO blend.

Taas-Yuriakh is due to load 430,000 tonnes of ESPO from the Pacific port of Kozmino in the April to June period, according to the loading schedule. It said the maintenance will not affect the supply schedule.