By Maki Shiraki and Kentaro Okasaka

TOKYO (Reuters) -Nissan is betting on a new version of its Leaf electric vehicle (EV) to revive its fortunes, having gone from mass-market EV pioneer to laggard since its first model entered showrooms in 2010.

The Japanese carmaker's third-generation Leaf was launched on Tuesday and will go on sale in the United States in the autumn, with other regions to follow. But its success is far from certain in the face of significant obstacles.

The cars sold in the U.S. will be made at Nissan's factory in Tochigi, Japan, and therefore subject to tariffs. EV demand in the U.S., meanwhile, has cooled as customers clamour for hybrids, which Nissan still does not offer in America.

"There is a high possibility that this is going on sale at the worst possible time, given the imposition of tariffs and the Trump administration's rollback of EV subsidies," said Koji Endo at SBI Securities.

"If the new Leaf doesn't sell, it will mean big trouble for Nissan."  

The price of the new Leaf has yet to be announced, but the previous hatchback styling has been overhauled as a crossover with battery capacity up to 25% more than the previous version. Nissan estimates a maximum range of up to 303 miles in the U.S. with its 75 kWh battery.

Even with the tariffs, the U.S. price will be competitive, a Nissan spokesperson said.

It is difficult to understate the Leaf's symbolic importance to Nissan.

It was the world's best-selling EV for years until it was overtaken by Tesla. Introduced by the now-disgraced Carlos Ghosn, it heralded Nissan's desire to play a big role in the electric future. Despite the company's troubles in recent years, it has sold almost 700,000 Leaf vehicles.  

Chief Executive Ivan Espinosa now faces the difficult task of delivering much-needed cost cuts while continuing to invest in development of new vehicles to refresh its ageing line-up and lack of hybrids in the United States. 

Espinosa has laid out plans for big cuts, including seven plant closures and 11,000 jobs. That will bring staff cuts to about 20,000, including those announced by his predecessor last year.

Nissan reported a net loss of about $4.5 billion in the past financial year and faces 596 billion yen ($4.1 billion) in debt due next year. 

The new Leaf will also be made at the Sunderland factory in Britain. The Tochigi and Sunderland plants are not expected to be among the closures, though the Oppama factory where the Leaf was first made could be axed. 

(Reporting by Maki Shiraki and Kentaro OkasakaWriting by David DolanEditing by David Goodman)