Nissan's new boss pledged Monday to regain customer trust and harness the firm's three-way alliance with Renault and Mitsubishi, as the crisis-hit firm seeks to turn the page from the arrest of former chief Carlos Ghosn.

In his first comments since taking the reins at the auto giant, Makoto Uchida acknowledged the firm had made mistakes in its internal corporate culture and faced a "difficult" financial environment.

"There are three words that guide me -- respect, transparency and trust," said Uchida, new boss of a company battered first by a falsified data scandal and then the alleged financial misconduct of Ghosn, who denies all charges.

"I want our employees to feel proud that they work for Nissan. If we can do this, we will regain the trust of our customers," said the 53-year-old.

But the new CEO has a mountain to climb to restore Nissan to health in an industry in turmoil and undergoing once-in-a-generation restructuring.

Only last month, the firm was forced to slash its full-year forecast for both sales and profits, admitting it had been hit by weak demand in Japan, the US and Europe.

This came as Nissan reported its worst first-half results since the global financial crisis a decade ago.

"Please allow me to express my sincere regrets. I cannot overstate how seriously we are taking this situation," said Uchida.

Nissan Motor's new president and CEO Makoto Uchida has a lot of homework to do to restore the firm to health
Nissan Motor's new president and CEO Makoto Uchida has a lot of homework to do to restore the firm to health AFP / Behrouz MEHRI

"The recent issues around final inspections in Japan and executive misconduct revealed serious operational management issues and weak corporate governance. This didn't just damage our reputation," he admitted.

"By trying to hit overambitious goals, we caused a rapid decline in our performance."

Former chief executive Hiroto Saikawa resigned in September after an investigation prompted by the Ghosn scandal revealed he too was among Nissan executives who received excess pay by altering the terms of a share price bonus.

Uchida inherits the harsh cost-cutting measures Saikawa proposed as a way out of the crisis -- including reducing dealer incentives and promotions but also cutting global production by 10 percent to 2023 -- a measure that means the loss of 12,500 jobs.

He declined to offer an update on this programme but insisted that "fixed costs" needed to be reined in.

Turning to the uneasy alliance between Nissan, Renault and Mitsubishi Motors, Uchida simply said that the automakers "must focus on improving revenue and profits of one another" while stressing the "independence" of the Japanese firm.

Renault holds 43 percent of Nissan, which has in turn has a 15 percent stake in Renault and a 34 percent controlling stake in Mitsubishi Motors.

Uchida said he had had no discussions about changing this structure, which came under pressure as the "junior partner" in the tie-up, Nissan, outgrew Renault.