Bermuda-based shipowning and chartering firm SFL has agreed to purchase four modern Suezmax tankers for an aggregate price of $222.5m.

The transaction also covers the vessels’ long-term time charters to a subsidiary of Koch Industries.

SFL plans to take delivery of the vessels between August and October.

Constructed in 2015 and 2020, the four vessels have advanced eco-design features, including exhaust gas cleaning systems.

The six-year charter period of the vessels will add around $250m to the shipping company’s fixed-rate backlog, stated SFL.

The charterer has an option to pay a termination fee and end the charters after three years.

Another option is to develop a sale of one or more of the tankers from year four of the charter period, which also involves a profit share arrangement with SFL.

SFL Management CEO Ole Hjertaker said: “We are pleased to further expand our presence in the tanker market at what we believe is an attractive point in the cycle with a historic low order book in the segment.

“The transaction demonstrates our standing in the market as a high-quality provider of transportation services for industry-leading customers, and we continue building our fleet and charter backlog with accretive acquisitions.”

Last November, SFL agreed to acquire four modern Aframax LR2 product tankers for $160m.

The firm also reached long-term time charter agreements for the vessels with a unit of Trafigura.