German utility Uniper signed a contract with Japanese group Mitsui OSK Lines to build and charter a ship to handle deliveries of liquefied natural gas (LNG) into Germany's planned terminal at Wilhelmshaven (LTW), it said on Tuesday.

LTW, a subsidiary of Uniper, is the project developer and operator behind the potential LNG terminal at the deep-sea port on the North Sea coast.

Germany wants to diversify from pipeline gas from the Netherlands, Norway and Russia, while LNG exporters are seeking marketing opportunities in a region whose indigenous gas supplies are decreasing fast.

Known in the industry as a floating storage and regasification unit (FSRU), the ship, designed in accordance with German requirements, will be built at a South Korean shipyard by Daewoo Shipbuilding Marine Engineering and chartered by LTW for 20 years, Uniper said in a statement.

It will provide 263,000 cubic metres of storage capacity and feed regasified gas through port facilities into onshore transmission grids.

Uniper board member David Bryson said his company would handle access to customers of LNG in Europe and open up new supply channels for its customers.

Uniper sold 220 billion cubic metres of gas last year, more than double Germany's consumption.

"The agreement to build and charter this FSRU is an important milestone for both parties on the journey to establishing and LNG terminal in Wilhelmshaven," he said.

Commercial realisation of the project will move ahead over the coming summer when a tender process will test customers' readiness to express binding interest in bookings, he said.

Alternative projects for German LNG terminal locations include Brunsbuettel on the Kiel canal and the inland river port Stade.

(Reporting by Vera Eckert, editing by Barbara Lewis)