French artificial-intelligence firm Mistral AI is negotiating with investors, including Abu Dhabi-backed fund MGX, to secure as much as $1 billion in new equity financing, according to people familiar with the discussions. The round could value the Paris-based generative-AI specialist at about $6.2 billion, underscoring continued investor appetite for European AI start-ups despite a broader slowdown in venture funding. Terms have not been finalized, and the size or composition of the investment could still change.