How much does it cost to operate a supertanker?

I'm trying to find out who built the M. Star supertanker.

I watched the construction of one of the 1st Supertankers,the Nisho Maru, in SSK Shipyard in Sasebo Japan in 1962. Ships are measured by DWT (Dead Weight Tons) witch is a measurement of the weight of the water it displaces when fully loaded. The Nisho Maru came in at 130,000 DWT. It wasn't more than a year later when Mitsubishi Shipyards in Nagasaki Japan built a supertanker more than twice that size.

The "M Star" which may have been attacked in the Strait of Hormuz is a 320,000 DWT

which carries a cargo capacity of 220,000 tons of crude oil.

I want to know who built this ship. Hyundai of South Korea builds supertankers; maybe they built it.