BRUSSELS, Nov 25 (Reuters) - The European Commission on Friday approved a joint venture between two privately held German makers of air conditioning and engine components, Behr Service and Hella KGaA Hueck & Co. The new venture, to be called Behr Hella Services GmbH, will be a supplier of car engine cooling and air conditioning components. "The Commission concluded that the transaction will not significantly impede effective competition in the European Economic Area or any substantial