Shiga, a lifelong employee of Nissan, will effectively be its most senior executive permanently based in Japan as Ghosn will also become chief executive and chairman of French auto maker Renault SA, Nissan's top shareholder, from May.
"He's creative and persistent and has a good relationship with Ghosn," said Christoper Richter, an auto analyst at Merrill Lynch.
Ghosn has been credited with pulling Nissan back from near-bankruptcy since assuming the post of chief operating officer in 1999, and has steered it towards profitability.