Robert E. Rubin, director, chairman of the executive committee and member of the office of the chairman of Citigroup, has resigned from the Ford board of directors.

He joined Ford’s board in 2000.

In a letter to Bill Ford, chairman and CEO of Ford Motors, Rubin said: "As the board undertakes its upcoming review of strategic options, Citigroup's multi-faceted relationship with Ford could raise a question whether my relationship with Ford and Citigroup creates an appearance of conflict.

"Although no conflict currently exists and while I would have liked to remain involved, I have with great regret concluded that I should resign from the board at this time."