Miami-based SunStone Ships has firmed up the latest cruiseship newbuilding in its series in China.

The company said a deal has been signed for the Infinity Class-vessel at China Merchants Heavy Industry.

SunStone president and CEO Niels-Erik Lund said: “We have worked diligently in obtaining the long-term charters and shipbuilding orders for the Infinity Class vessels and we continue to move forward with the contracts and building at a very satisfactory speed, safety and quality level”.

The 104-metre ships will carry between 130 and 200 passengers and 85 to 115 crew.

They are ice-class 1A and designed by Ulstein Design & Solutions.

The sixth ship already has a long-term charter agreement in place, the owner said, with delivery set for September 2021.

"SunStone is in negotiations for four additional vessels where it is expected that Infinity vessel number seven will be signed within May and the remaining three options will be signed within 2019."

Lund told TradeWinds last month: “We are very pleased with the relationship with China Merchants group and the development and speed with which we are signing these newbuild contracts."

The original order was for four firm ships with six options.