WeWork is locked in negotiations this week with its largest shareholder, Softbank Group Corp, over a new $1 billion investment to enable the shared office space company to go through a major restructuring, according to sources familiar with discussions. If the talks are successful, WeWork, which had to abandon an initial public offering last week because of investor concerns about how it was valued and its business model, will seek to negotiate a $3 billion debt deal with JPMorgan Chase & Co , the sources said. WeWork and SoftBank did not immediately respond to requests to comment.