The US shipowner said Friday it had placed firmcontracts for four 50,000-dwt tankers in a deal worth $500m.

The first four ships are due for delivery in2015 and 2016. If the four options are exercised deliveries will stretch through2017.

In addition to construction APSI will share in theeconomics of the operation and chartering of the new vessels with Crowley.

APSI expects to makean investment of about $115m in the first four vessels of the partnershipthrough a combination of existing shipyard equity and new debt.