The automobile giant's statement came a week after Ghosn, 65, had appeared in Beirut while under strict bail conditions in Japan, reports Efe news.
Ghosn was due to appear before Tokyo courts in the coming months in connection to charges of financial irregularities during his tenure at the helm of Nissan Motor.
"As stated by the public prosecutor's office, former chairman Carlos Ghosn's escape to the Lebanese Republic without the court's permission in violation of his bail conditions is an act that defies Japan's judicial system. Nissan finds it extremely regrettable," the statement said.
Ghosn is accused in Japan of financial misconduct, including underreporting his compensation from Nissan and misappropriation of the company's assets for personal gain.
He was first arrested on November 19, 2018 and then on April 25, 2019. He was later released on bail, with restrictions on communications and movement, and a ban on leaving the country.
"Nissan discovered numerous acts of misconduct by Ghosn through a robust, thorough internal investigation. The company determined that he was not fit to serve as an executive, and removed him from all offices," the company statement said.
It added that an internal investigation found "incontrovertible evidence of various acts of misconduct by Ghosn".
The consequences of this case for Nissan had been significant, it said, and another investigation by the US Securities and Exchange Commission concluded that Ghosn's conduct "was fraudulent". French investigations were also ongoing.
"Nissan will continue to do the right thing by cooperating with judicial and regulatory authorities wherever necessary," it said, adding that Ghosn's escape would not affect Nissan's "basic policy of holding him responsible for the serious misconduct uncovered".
Japanese authorities have asked Interpol to issue a red notice against Ghosn and await his return to Japan over charges against him in the courts. His trial was to be held in April.
Chief Cabinet Secretary Yoshihide Suga said on Monday night that Japan will make every diplomatic effort to get Lebanon to hand over Ghosn to the Japanese authorities.
The two countries do not have an extradition agreement.
( With inputs from IANS )