Nordic American Tanker Shipping (Nat) is buying its 18th vessel, a double-hull Suezmax tanker, for $51.5m.

The Bermuda-based shipping firm expects the vessel to operate in the spot market or on spot market-related charters.

This is despite news this week that Nordic posted a quarterly loss with dividends down by 80% following problems with the spot frieght market for oil.

According to a report by Reuters, the average daily rate for Nordic’s spot vessels was $14,075 per day net during the third quarter. The daily rate for the second quarter was $26,300.

The tanker, built in the Far Eastern Shipyard in 2002, will be delivered by March 2010.

During 2009 NAT acquired three vessels and entered into an agreement to acquire a fourth, increasing the trading fleet from 12 to 16 vessels.

Until August 2010, NAT expects its fleet to grow to 18 vessels, increasing the dividend and earnings potential by 50%.