Ghosn was arrested for the fourth time last week on suspicion that he had tried to enrich himself at Nissan's expense, to the tune of $5 million.
He is also awaiting trial on other charges of financial misconduct and aggravated breach of trust. Ghosn, who had been released on $9 million bail in early March after spending 108 days in jail, has denied all allegations against him.
Ghosn's initial detention period was set to expire on Sunday, and had been widely expected to be extended by the maximum 10 days. Public broadcaster NHK said it was rare for prosecutors' full extension request to be denied and shortened.
Ghosn's defence team has launched a public and fierce battle against Tokyo prosecutors, calling the latest arrest "illegal" in documents seen by Reuters.
Later on Friday, a court rejected the defence team's appeal against the extension, meaning that the team may have to make a fresh bail application if Ghosn is indicted on further charges at the end of his new detention.
Once celebrated as a saviour of a near-bankrupt Nissan 20 years ago, Ghosn has been ousted as chairman of Nissan, Renault SA and Mitsubishi Motors Corp since his arrest, jeopardising the auto-making alliance he masterminded.
The court decision came as several dozen executives and board members from the three automakers gathered in Paris for an alliance anniversary dinner described by one participant as "simple, nothing ostentatious".
New Renault Chairman Jean-Dominique Senard told managers they had proved their ability to "overcome our differences and keep the alliance strong", also invoking a need for quality improvements and swift joint decision-making, sources said.
Senard and the three carmaker CEOs also met on Friday for a monthly alliance board meeting, followed by a presentation to the larger group of Renault vehicles in development.
(Reporting by Tokyo Newsroom; Editing by Christopher Cushing/Keith Weir)
