Overseas Shipholding Group (OSG) will hang on to a quartet of American Shipping Company tankers for another three years.

OSG, the New York-listed Jones Act player, said the deals tack another three years onto the back of charters ending next December, keeping them under control until December 2023.

"The decision to further extend the maturities of each of the four vessels underscores our confidence that the continuing move towards balance in the Jones Act tanker market is an opportunity to serve our core customers in a rate environment that will provide attractive returns over time," chief executive Sam Norton said in a statement.

The ships, according to American Shipping Company's website, are the 46,804-dwt Overseas Boston (built 2009), the 46,666-dwt Overseas Nikiski (built 2009), the 46,666-ddwt Overseas Martinez (built 2010) and the 46,656-dwt Overseas Anacortes (built 2010).

The Oslo-traded company owns 10 ships, all chartered to OSG. All of them have three- or five-year extensions available to OSG indefinitely. The companies also have a profit-sharing agreement.

For the third quarter, OSG posted a $3.8m loss, but raised its Ebitda forecast for the fourth quarter to $30.3m, a sequential doubling, alongside projected time charter equivalent growth of $13m to $89.5m.

On the earnings call, Norton said the fundamentals of the Jones Act tanker market had reached "a healthy equilibrium" with strong rates expected.

After the close Wednesday, OSG shares were down $0.04, or 2.19%, to $1.79.