Oil tanker Destan, carrying about 740,000 barrels of Russian oil for refiner Indian Oil Corp , has been waiting for more than 10 days to berth at a port in western India because of a technical issue, five sources familiar with the matter said.

Indian companies including the country's top refiner IOC buy Russian oil on a delivered basis and their liability arises only after the discharge of the cargo.

Sources said there were technical issues with the vessel that are preventing it from berthing.

The vessel arrived at Vadinar port on July 22-23 carrying 99,000-100,000 metric tons, according to two of the sources.

"There is some problem with the main engine", one of them said.

Two other sources said the master of the vessel was seeking permission for a trial berthing on Monday.

A fourth source said the vessel may discharge oil sometime this week.

IOC did not respond to a Reuters email seeking comment.

According to LSEG trade flows, Panama-flagged Destan is loaded with 80,000 tons of ESPO blend crude and started sailing to Vadinar on June 30 from Russia's Pacific port of Kozmino.

Victory Shipping & Marine Inc is the registered owner of the vessel.

Indian Register of Shipping (IRClass) has provided safety certification for Destan.

IOC buys Russian oil from spot markets after its previous annual oil purchase deal was not renewed for this fiscal year to March 2025.

(Reporting by Nidhi Verma; Editing by Mark Potter)