Qatar's real estate investment arm said on Wednesday it had signed an initial deal with German railways Deutsche Bahn to plan a multi-billion dollar rail project in the Gulf Arab state.

The partners would develop the conceptual design for integrating Qatar's planned railways into a comprehensive national railway system, Qatar Diar Real Estate Investment Company said in a statement.

Qatar Diar is a unit of sovereign wealth fund Qatar Investment Authority. Qatar is the world's biggest exporter of liquefied natural gas.-Reuters