A deal would end the current alliance between the companies and marry them as one corporation, said the people, who asked not to be identified as the details aren’t public. Renault currently owns 43% of Nissan while the Japanese carmaker has a 15% stake in its French counterpart. Carlos Ghosn, the chairman of both companies, is driving the negotiations and would run the combined entity, the people said.

The parties are discussing a transaction in which Nissan would essentially give Renault shareholders stock in the new company, the people said. Nissan shareholders would also receive shares in the new company in exchange for their holdings, they said. The automaker may maintain headquarters in both Japan and France.

Renault shares jumped as much as 8.3% in early trading Thursday, hitting the highest intraday level in more than a decade. They were up 4.2% at 10:05 a.m. in Paris, giving the company a market value of about 29 billion euros ($36 billion). Nissan shares are down nearly 2% over the past year, giving the company a valuation of 4.6 trillion yen ($43 billion).

Getting a deal done could prove very difficult, the people said. The French government owns 15% of Renault and may be reluctant to relinquish control over its stake or have its position watered down. Both the French and Japanese governments would also have to approve a deal and may have strong opinions on where the combined company is domiciled, the people said.

One possibility would be to base the company in London or the Netherlands, where cross-Atlantic carmaker Fiat Chrysler Automobiles NV has its corporate charter. Fiat Chrysler maintains headquarters in both Italy and the U.S.

No final decisions have been made and the talks, which have been ongoing for several months, may not result in a deal, they said.

A spokesman for the Renault-Nissan alliance said the group doesn’t comment on rumors and speculation, while a spokesman for the French finance ministry declined to comment. Representatives for Yokohama, Japan-based Nissan and Renault also declined to comment.

Reuters reported earlier this month that Nissan was in talks to buy the bulk of the French government’s stake in Renault, citing unidentified people. The Renault-Nissan alliance said at the time any discussion about a share transaction involving the parties was “pure speculation.”

Ghosn has pledged to cement Renault’s partnership with Nissan, saying in February that the companies would devise a plan to “make the alliance irreversible.” The 64-year-old relinquished the chief executive officer role at Nissan last year to focus on the partnership.

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The companies are seeking to double synergies to 10 billion euros ($12.2 billion) by 2022 from 2016. In April, Mitsubishi Motors Corp. — in which Nissan is the largest shareholder — will further integrate with the alliance by joining a shared parts-purchasing organization.

The alliance forecasts unit sales of 14 million units by 2022, compared with 10.6 million last year. Volkswagen AG, the world’s largest carmaker, sold 10.7 million vehicles last year.

While the companies have claimed a multitude of benefits from their partnership, its staying power could be complicated until imbalances in the companies’ ownership structures are resolved.

Ghosn reiterated last month that Japan wouldn’t agree to a tighter structure if France remains a shareholder. He also said he isn’t trying to convince the French state to reduce its stake in Renault.

“They decide to be here or to get out,” he said. “Frankly, I don’t even open this subject. I just consider that I have the shareholders that I have and I try to satisfy them in the best way possible and as much as possible make sure that they understand our strategy and appreciate our results.”