Carlos Ghosn, the Brazilian-born chairman of Nissan, credited with reviving its fortunes over the past two decades, was detained on allegations of under-reporting his own income and misusing company assets.
The scandal - the latest in a string to affect Japan Inc. - wiped millions off the stock value of all three companies but Nissan bounced back marginally in opening Tokyo trade, climbing almost half a percentage point in a falling market.
"There's no question Carlos Ghosn is being used as a symbol to ensure that corporate leadership in Japan will stay close to its workers".
There was no update Wednesday in Tokyo from prosecutors on Ghosn's case, and no public word from Ghosn himself. Under Japanese law, the pair can be kept in custody for up to 23 days without charge.
Monday's arrest of the millionaire auto tycoon, who is credited with turning around the Nissan-Renault-Mitsubishi Motors alliance, sent shockwaves through the global vehicle sector and corporate Japan.
Ghosn and Greg Kelly, a representative board member, were arrested on November 19 on suspicion of violating the Financial Instruments and Exchange Law.
Following Ghosn and Kelly's arrests, which were based in part on evidence gathered in a Nissan internal investigation, details have begun to emerge on some of the alleged financial transgressions the pair are suspected of.
Mr Saikawa's influence at Nissan will grow in Mr Ghosn's absence.
"Ghosn is likely the most successful foreign chairman in Japan", said Kosuke Sato, a senior economist at the Japan Research Institute.
After an emergency meeting Tuesday, Renault announced that independent director Phillippe Lagayette would take over as interim chairman for the automaker and Chief Operating Officer Thierry Bollore will take over as interim CEO. In a letter to Renault employees, he pledged "full support" for Mr Ghosn and to protect the Nissan partnership. Japanese authorities shocked the world when they arrested Ghosn on Monday, catching Renault and the French government flat footed, and fueling speculation about whether Ghosn was ousted in a palace coup.
"This leadership guarantees the correct functioning of the Renault company", French Economy Minister Bruno Le Maire told reporters on Wednesday.
Nissan has told Renault board members that the company is looking into potential wrongdoing at the alliance's Amsterdam-based joint venture, RNBV, according to three people familiar with the matter.
Renault owns a 43 per cent voting stake in Nissan, which owns just 15 per cent of Renault - without voting rights.