After soaring on news of potential merger, fall reflects concerns about expected terms of deal, say analysts

Shares in the Japanese carmaker Nissan have tumbled in their biggest fall since August’s stock market sell-off, as investors turned their attention to the company’s planned tie-up with domestic rivals Honda and Mitsubishi.

Nissan’s shares fell by as much as 15% on Friday, before regaining some losses to close down 7.8%, in a sign of investor volatility.