PARIS, May 13 (Reuters) - The French government on Monday promoted a private sector plan to develop a nickel and cobalt refinery near Bordeaux to reinforce the country's supply chain for electric vehicle batteries and reduce its reliance on China.

The 300 million euro ($323.49 million) project from Swiss-based KL1, presented as part of President Emmanuel Macron's annual "Choose France" investment event on Monday, aims to process 20,000 metric tons of nickel and 1,500 tons of cobalt per year from 2028 in a port zone on France's Atlantic coast.

The project, called Electro Mobility Materials Europe (EMME), aims to cover 20-30% of France's nickel and cobalt needs for electric vehicles by 2030.

France and other European countries have been investing in gigafactories to produce batteries and developing mines for minerals like lithium. But capacity to process metals into high-purity materials suitable for batteries continues to be dominated by Chinese companies.

"This will allow us to fill a gap in the value chain," French Finance Minister Bruno Le Maire said of the project during a weekend call with reporters.

The project, which is going through public consultation and administrative approval stages, could benefit from a green industry tax credit worth around 20% of the investment cost, the finance ministry added.

France has a large nickel mining industry in its South Pacific territory of New Caledonia and KL1 is headed by Antonin Beurrier, a former CEO of New Caledonian nickel producer Prony Resources.

However, a finance ministry spokesperson said it had not been decided yet where the nickel and cobalt would be sourced from for the planned refinery.

The French government has been negotiating a rescue package for the loss-making New Caledonian nickel sector, including a commitment to supply Europe's battery supply chain, though talks have stalled amid political tensions between pro-independence and loyalist parties.

($1 = 0.9274 euros) (Reporting by Gus Trompiz and Sudip Kar-Gupta; Editing by Susan Fenton)