The EU is preparing a law to make life easier for its green industry through state aid and a European Sovereignty Fund with the goal of keeping firms from moving overseas, the head of the European Commission said on Tuesday.

Brussels is concerned that European companies will increasingly move to the United States, which has a $369 billion scheme to subsidise green production.

"The idea is good and goes in the right direction, as Europe cannot run the risk of deindustrialisation, cannot lose to the U.S. in this process," Fernando Medina told Portuguese broadcaster RTP on the sidelines of a meeting of the bloc's finance ministers in Brussels.

"But it has to be implemented through European mechanisms that ensure equality within the European space," he added.

Medina said it was crucial to work out the plan's details, because "if SMEs can't access it, or if it's just for technologies or industries in certain countries, it could end up only targeting the more industrialised countries in central Europe and not ensure a level playing field."

"The smaller European countries cannot lose to the larger countries in an internal competition that would not make sense to open at this moment," he said.

(Reporting by Sergio Goncalves; Editing by David Latona and Bernadette Baum)