Marchionne has long advocated more tie-ups in the industry to share the prohibitive costs of making cleaner and more technologically advanced vehicles, but GM has firmly rebuffed his previous advances.

“I never close any doors. I may shamelessly try and knock again … on the GM door or any door if I thought it was a good thing for the business. Absolutely, without even blinking,” Marchionne told reporters at the Geneva car show.

“The desirability of GM as a potential merger candidate remains untouched.”

FCA’s share price shot up last month on the day the news of the talks between GM and PSA first emerged, with some analysts suggesting GM could be tempted to subsequently regain a foothold in Europe through FCA, which is more profitable than the Opel business that has been loss-making for many years.

Others, however, said GM would have even less interest than before to combine with its smaller and heavily-indebted rival, which controls only 7 percent of the European market and whose operating profit margin of 2.5 percent there lags rivals.

“GM will de-consolidate a loss-making asset and improve return on capital, something that investor have blamed the company for in the last years, making a deal with FCA less likely,” said Angelo Meda, head of equities at Banor SIM, adding that the number of options for FCA were reducing.

“Lagging behind peers on hybrid/electric vehicles, without a deal in the next two to three years the main risk is a step up in investments, which would dampen the already weak, compared to peers, cash generation.”

Marchionne said the PSA-Opel deal would reduce potential synergies FCA-GM might reap from a tie-up by around 15 percent, but the prospective benefits were still worth pursuing.

But industry sources said GM had no interest in FCA, not least because any merger between the two big U.S. carmakers would bring major job losses and therefore stiff union opposition.

With the North American market where FCA makes 85 percent of its profits peaking, analysts also questioned why anyone would buy the company now, when the price could be set to fall.

However, Marchionne also has his eye on other possible partners, saying Volkswagen, could be an attractive prospect. With PSA now set to become the second-biggest car producer in Europe with the acquisition of Opel, the German group could be interested in talks, he said.

“I have no doubt that at the relevant time they may show up and have a chat,” he said.

In the meantime, FCA plans to concentrate on completing the shift of production at its plants in Italy towards higher-margin vehicles such as Jeeps, Alfa Romeos and luxury Maseratis.

Production for its other cars would be moved elsewhere, he said, adding that the popular Fiat Panda could be returned to FCA’s plant in Poland from 2020.