PARIS — A week after the collapse of a potential merger with Fiat Chrysler, the French automaker Renault is pressing to strengthen ties with Nissan, its partner in a decades-old auto alliance, to stay competitive in the global car market, the company’s chairman said on Wednesday.

Speaking to more than 900 Renault shareholders in Paris, Jean-Dominique Senard, the chairman, acknowledged that there was “a tense climate” between his company and Nissan. “But,” he added, “the good news is that nothing is irreparable.”

Mr. Senard and Hiroto Saikawa, Nissan’s chief executive, face scrutiny for failing to shore up the world’s largest auto alliance six months after Carlos Ghosn, who led the joint entity, was charged with financial misconduct. Mr. Ghosn’s arrest set off a destabilizing chain of events at the two companies.

The strained relationship has deteriorated further in recent days. Mr. Senard said last week that Renault would block a proposed overhaul of Nissan’s governance because the new system would deprive his company of adequate representation on the Japanese carmaker’s new three-committee board.