By Maki Shiraki and Daniel Leussink

YOKOHAMA, Japan (Reuters) - The boards of Nissan and Honda voted on Thursday to officially end talks to merge the Japanese automakers, two people familiar with the matter said.

A tie-up would have created the world's fourth-biggest auto group by vehicle sales after Toyota, Volkswagen and Hyundai.

Nissan, Japan's third-largest automaker, backed out of the talks with larger rival Honda after negotiations were complicated by growing differences, including Honda proposing that Nissan become a subsidiary, sources have previously said.

Representatives for the companies declined to comment on the matter. The sources were not authorised to speak to media and declined to be identified.

The automakers, which are due to report quarterly earnings later on Thursday, had been in talks to merge since late December.

Both Nissan and Honda have seen their industry and the key China market upended by the rapid rise of Chinese electric-vehicle makers such as BYD, and both are facing the prospect of tariffs in the United States, another major market.

Nissan is pushing ahead with a restructuring plan announced in November that includes cutting 9,000 jobs and reducing global capacity by 20%. It has yet to disclose details such as which locations will be affected.

Sources said in December that Nissan will need to further reduce its capacity in China, where it operates eight factories through its joint venture with Dongfeng Motor. It has already suspended production at its Changzhou plant as part of efforts to optimise operations.

Before announcing the merger discussions in December, Nissan and Honda had been holding separate talks on a technology collaboration, which they could outline the scope of on Thursday.

Nissan is now open to working with new partners, with Taiwan's Foxconn seen as one candidate, sources told Reuters last week.

Foxconn Chairman Young Liu said on Wednesday that it would consider taking a stake in Nissan but that its main aim was cooperation.