PARIS - Nissan's investigation into alleged misconduct by Chairman Carlos Ghosn is expanding to include Renault-Nissan finances, sources told Reuters - a sign that Nissan may seek to loosen its French parent's hold on their global carmaking alliance.

Nissan told Renault's board on Monday it had evidence of potential wrongdoing at Renault-Nissan BV, the Dutch venture overseeing alliance operations under Renault's ultimate control, three people with knowledge of the matter said.

The private communication from Nissan Chief Executive Hiroto Saikawa came as the Japanese carmaker, 43.4 percent-owned by Renault, announced that an investigation had uncovered misconduct involving Ghosn including under-reporting of his compensation and personal use of company assets.

Renault and Nissan both declined to comment.

(Additional reporting by Gilles Guillaume in Paris Editing by Keith Weir) ((laurence.frost@thomsonreuters.com; +33 1 4949 5683;))