US-listed Nordic American Tankers said on Thursday that it had struck a deal to add another vessel to its suezmax fleet.

The agreement for the unidentified South Korean-built ship takes the Herbjorn Hansson-led shipowner’s suezmax-only fleet to 20. Seven of them are aged more than 15 years.

NAT said the vessel had been operated and well-maintained by a “top shipowner” for the last six or seven years.