By Maki Shiraki and Daniel Leussink

TOKYO (Reuters) -Nissan and Renault will make an announcement in the coming days on their restructured alliance and have finalised the deal, people familiar with the matter said, capping 10 months of sometimes tense negotiations.

The automakers announced a framework agreement in February and had aimed to finalise the deal as early as March. Under the framework, the Japanese automaker would take as much as 15% of Renault's new electric vehicle unit, Ampere, while Renault would reduce its 43% stake in Nissan.

But that timeline slipped when senior Nissan executives and some directors challenged detailed provisions of deal and the benefits and protections for Nissan's intellectual property, Reuters has reported.

The delay shows how the latest tension at the top of the Japanese automaker has complicated a drive to bring the decades-long relationship with Renault to a more equal footing. After the automaker was pitched into turmoil by the ouster of former Chairman Carlos Ghosn, Nissan executives sought to rebalance the alliance he built.

Nissan has been working to define a lower threshold for its pledged strategic investment in Renault's electric vehicle unit, Ampere, below the 15% maximum target it announced in February, two of the people said. The size of its stake still hinges on the value of Ampere, but Nissan is likely to take less than 10% of the new unit, one of them said.

The announcement is expected in the coming days, three people familiar with the matter said. All of the people declined to be identified because the information is not public.

"Nissan and Renault are engaged in constructive and ongoing negotiations. We will make a statement in due course when the agreements are concluded," the Japanese automaker said in a statement.

Renault declined to comment. The French automaker has said it expects to list Ampere in an initial public offering in the first half of 2024. Sources have said the unit could be valued at up to 10 billion euros ($11.2 billion).

IP CONCERNS

Renault wants to attract more investors to Ampere, given the massive investment required for next-generation connected cars. Nissan and Renault's junior partner, Mitsubishi Motors, has also indicated it may invest in the company. U.S. chip giant Qualcomm has already said it will invest.

But the possibility of additional partners has underscored for Nissan the need to protect its intellectual property in any future collaboration, Reuters has reported.

Discussions have focused on how to deal with future IP - including technology that may not yet exist, one of the people said. A Mitsubishi spokesperson said it was still considering investing in Ampere but that nothing had been decided.

At the same time, Nissan's board has been investigating a claim that Chief Executive Makoto Uchida carried out surveillance of his then-deputy, Ashwani Gupta, to acquire leverage to remove him from the company because of Gupta's opposition to some terms of the new partnership with Renault, Reuters has reported.

Gupta, who had been chief operating officer and was widely seen as a candidate to become Nissan's CEO, left Nissan at the end of June.

($1 = 0.8913 euros)

(Reporting by Maki Shiraki and Daniel Leussink; Editing by Kevin Krolicki, David Dolan and Christian Schmollinger)