PARIS, Dec 11 (Reuters) - The head of Dubai's Emirates issued a furious reaction to a public suggestion by Airbus that it might discontinue the A380 superjumbo and told Reuters it was ready to invest massively in an upgraded version if the planemaker went ahead with it.

Tim Clark, president of Emirates airline, said he had protested to Airbus after its finance director aired the possibility of cancelling the world's largest airliner project due to poor sales.

"I am not particularly happy as you can imagine," Clark said in a telephone interview.

Finance Director Harald Wilhelm told analysts on Wednesday that Airbus would be able to breakeven on the A380 through 2018 "if we would do something on the product, or even if we would discontinue the product".

Clark said that if Airbus, on the contrary, went ahead with proposals to upgrade the A380 by adding new Rolls-Royce engines, Emirates would eventually replace all the 140 A380s it has ordered with the newly upgraded version which would improve fuel efficiency by 12-15 percent from 2020.

He said the comments would "not help" the future second-hand value of A380 aircraft, but that he was not worried about financing new deliveries. He said the aircraft was popular with passengers and flying "full to the gunwales".

He also said Emirates would soon begin studying an order for 50-70 mid-sized Airbus or Boeing wide-body jets.

(Reporting by Tim Hepher, editing by Geert De Clercq)