They said the company would increase LPG loadings to 52,000 metric tons from 43,000 tons in May.
LSEG data showed Sibur's LPG export volumes fell by 48% in January-May from last year. The drop reflected a shortage of tankers after a time-charter contract with a shipping company Navigator Gas expired in December, the sources said.
From June, Sibur has chartered two new gas carriers - Falcon and Negmar Min - capable of carrying 20,000 metric tons each and may increase its exports, they said.
"An LPG cargo (about 20,000 tons) is planned for loading on Falcon early in June," one of the sources said.
"The volume of supplies (LPG) through Ust-Luga will be determined by various factors, the logistics component is only one of them. The volumes are more influenced by the domestic demand and our own supply plans to the company’s petrochemical plants," a Sibur spokesperson said.
According to LSEG, Falcon is owned by Dubai-based Delta Overseas Shipping, and Negmar Min by Turkey's Negmar Denizcilik.
Negmar Denizcilik declined to comment while Reuters was unable to reach Delta Overseas Shipping for comment.
By chartering more carriers Sibur could further increase its exports from Ust-Luga. According to the sources, Russian Railways confirmed an ability to ship 86,000 metric tons of Sibur LPG to the port this month.
Sibur needs more tankers because voyages to end users take longer as the company increasingly ships to Turkey and the Middle East while European demand for Russian LPG remains low because of sanctions.
Ust-Luga is the main Russian port for LPG exports. It accounted for a quarter of all exports last year, with all the volumes supplied by Sibur.
LPG is widely used in the petrochemical industry as an alternative to naphtha and as a raw material. It is also used for heating and cooking and as an auto gas fuel.
