Tesla hands over keys to its technology on electric cars

Electric-car maker Tesla Motors is handing over the keys to its technology in an unusual effort to encourage other car manufacturers to expand beyond petrol-burning vehicles.

Tesla chief executive Elon Musk has promised to give away the company's entire patent portfolio to all comers, as long as they vowed not to engage in courtroom battles over intellectual property.

"If we clear a path to the creation of compelling electric vehicles, but then lay intellectual property landmines behind us to inhibit others, we are acting in a manner contrary to that goal," Musk wrote in a blog on the company's website on Thursday.

The decision opens the door to more collaboration with Tesla, which is making electric systems for Daimler and Toyota Motor Corp.

Other carmakers using Tesla's technology could potentially share the cost of Tesla's charging stations, for example.

Seven years after Tesla introduced the Roadster electric sports car, which it no longer makes, electric cars still make up less than 1 per cent of sales in the United States. Drivers remain concerned about their range and the lack of places to get a charge.