Renault shares plunge as profit warning deepens its problems

PARIS (Reuters) - A hefty profit warning sent Renault shares tumbling as much as 15% on Friday, capping a miserable year for the French carmaker following the arrest of long-time boss Carlos Ghosn and adding to signs of a sharp slowdown in the global auto industry.Renault and partner Nissan both announced changes in leadership last week, seeking to reboot their alliance after it was thrown into crisis last year by the arrest of Ghosn in Tokyo on financial misconduct charges, which he denies. ..