EU experts meet on Wednesday to tackle a French-German row over a delay by auto giant Daimler in using a new air conditioning coolant deemed more environment-friendly, officials said Monday.

The 28 European Union member states will gather for what an EU source told AFP would be a "technical" meeting focused on "points of law".

Germany and France are at risk of infringement action over the issue.

The dispute centres on France's refusal to allow certain new Mercedes vehicles (A, B and CLA-class models) for sale, in contravention of EU rules governing the free movement of goods across national borders.

Since January 1, EU norms demand that car makers use a refrigerant called R1234yf.

But Daimler is sticking to an older coolant, called R134a, as it claims studies have shown that the new gas catches fire more easily and puts cars at a greater risk of explosion in case of a crash.

The makers of R1234yf reject Daimler's claims but in Germany, the auto giant was given special permission to keep using the older gas, despite initial approval by the German Automakers Association, VDA, of which Daimler is a member.

Germany has until August 20 to answer queries from the European Commission, Brussels having another 10 weeks thereafter to decide whether to launch formal legal action.

Daimler argues that the cars blocked from sale in France were made during a six-month period of grace, a point Wednesday's talks will attempt to resolve.