PARIS/BERLIN (Reuters) - France’s Dassault Aviation said on Monday it had received a contract from the French government to update the Rafale fighter jet as plans simultaneously gather speed for a longer-term project to build a Franco-German successor.

The so-called F4 version of the multi-role Rafale, which is being developed for a reported investment of 2 billion euros (£1.78 billion), will include greater connectivity to allow "networked combat," Dassault said in a statement.

It will also involve upgraded sensors and optronics, a sophisticated helmet-mounted display and the integration of new air-to-air and air-to-ground weapons.

The upgrade to France’s national fighter programme comes as Paris and Berlin fine-tune plans to commission studies for a future Franco-German aerial combat system known as FCAS.

Two industry sources said the first-stage study contract, providing funding for design studies for a manned and unmanned system to replace the Rafale and rival Eurofighter, was expected to be signed at the end of January.

The venture is set to become Europe’s largest ever defence project and is being led by Dassault on behalf of the French aerospace industry and Airbus, whose defence arm is a partner in the four-nation Eurofighter, on behalf of Germany.

(The story was refiled to fix a typo in the first paragraph)

(Reporting by Tim Hepher, Andrea Shalal; editing by Richard Lough)