Full-year sales are now estimated at 10.6 trillion yen, down from a previous forecast of 11.3 trillion yen.
Nissan blamed the poor outlook on weak first-half earnings, a strong yen, an uncertain global outlook and the stagnation of the car industry in general.
Incoming chief financial officer Stephen Ma said: "Sales in China outpaced the market but sales in other key regions including the US, Europe and Japan underperformed in those markets. This resulted in the overall decrease of our market share."
Net profit for the six months to September plunged 73.5 percent to 65.4 billion yen, the worst first-half result since the global financial crisis a decade ago.
It was Nissan's first earnings announcement since the appointment last month of Makoto Uchida as new chief executive, elevating the insider heading the firm's China unit as it overhauls its leadership after the Ghosn scandal.
Uchida's appointment, to take effect on December 1, came after months of turmoil for the automaker in the wake of the arrest of former chief Ghosn on allegations of financial misconduct.
The two firms have made a show of holding the marriage together in the wake of Ghosn's arrest, but tensions have bubbled to the surface.
Renault holds a 43 percent stake in the Japanese automaker, which in turn controls 15 percent of the French firm but has no voting rights.
Ghosn is out on bail in Tokyo, awaiting a trial that reports have suggested could start in April on charges of under-reporting millions of dollars in salary and using company funds for personal expenses. He denies any wrongdoing.