Miami-based Sunstone Ships is poised to sign the third shipbuilding contract in a series of expedition cruise vessels to be built in China.

Sunstone ordered four firm vessels, with options for a further six, in a contract allowing the newbuildings to range between 100 and 200 passengers.

A steel cutting ceremony, attended by Sunstone’s chief executive Niels-Erik Lund, was held recently in China for the first ship in the series, the Greg Mortimer.