Nissan chief executive resigns after income allegations
The company employs 7,000 at its site in Sunderland, producing Qashqai, Juke, and zero-emission electric Leaf vehicles.
Board member Yasushi Kimura told reporters at the firm's headquarters in Yokohama that the board has approved Mr Saikawa's resignation, effective from September 16, and a successor will be appointed next month.
A search for the new chief executive is under way, he added.
Calls for Mr Saikawa's resignation, which arose after the arrest last year of his predecessor, Carlos Ghosn, on various financial misconduct allegations, have grown louder after Mr Saikawa acknowledged last week that he had received dubious payments.
The income was linked to the stock price of Nissan, and he said his pay was inflated by illicitly adjusting the date for cashing in.
The car maker's board met to look into the allegations against Mr Saikawa, as well as other issues related to Ghosn's allegations and corporate ethics at the company.
Mr Kimura said the income Mr Saikawa had received was confirmed as "not illegal".
Ghosn, who is on bail and awaiting trial, says he is innocent.
Mr Saikawa has not been charged.
"I have been trying to do what needs to be done so that I can pass the baton over as soon as possible," he told reporters earlier in the day, referring to his willingness to leave his job.
He did not attend the news conference.
Mr Saikawa has said he did not know about the improprieties, promised to return the money and blamed the system he said Ghosn had created at Nissan for the dubious payments.
Japanese media reports said Mr Saikawa had received tens of millions of yen – hundreds of thousands of pounds – in extra compensation.
Ghosn has been charged with falsifying documents on deferred compensation, which means he did not receive any of the money.
Nissan's profits and sales have tumbled over the past year.
Investors are also worried about Nissan's relationship with alliance partner Renault SA of France, which owns 43% of Nissan.
Ghosn was sent in by Renault to lead Nissan two decades ago.