Nissan Motor Co said on Tuesday it would add overtime and holidays at one if its Japanese factories towards the end of the business year in March to bring production of the Leaf electric car up to full speed.

Japan’s second-biggest automaker has gradually ramped up output of its first mass-marketed zero-emission car since it starting building the Leaf in late October, completing about 3,000 units to date. On Wednesday, the Leaf was named the 2011 European Car Of The Year, the first time an electric car has won the award.

By March, the pace of production will rise to full capacity of about 4,000 Leafs a month at the Oppama factory, south of Tokyo, putting Nissan on track to hit a target of producing a total 10,000 units by the end of March, a Nissan official said.

USA Today, however, said that among the 20,000 in the US who pre-ordered the Leaf all-electric car are going to have to wait months longer than they expected. Those who signed up to buy last summer, expecting delivery of the car this month or next, may have to wait as long as May or June.

“We’ll build more Leafs in the next two months and add overtime and holidays to keep up with production of the other vehicles on the line,” said Seiji Honda, head of the Oppama factory, noting that car demand typically ticks up at the end of Japan’s fiscal year in March.

Nissan, along with partner Renault SA, wants to lead the auto industry in the field of battery-run electric vehicles, and delivered its first electric vehicle (EV), the Leaf, to customers in Japan and the United States last month.

Until production starts at its Tennessee and Sunderland factories in 2012 and 2013, respectively, Nissan will supply the car from Oppama.

On Tuesday, Nissan invited journalists to tour the 430,000-units-a-year Oppama plant, where the Leaf hatchback is assembled on a mixed line alongside gasoline-engine models such as the Juke, Cube and Note.

With battery packs and electric motors waiting on the side of the trim and assembly lines instead of fuel tanks and engines, the Leaf’s frames flowed seamlessly on conveyor belts between those of the Juke crossover and Cube minivan.

The battery modules and other EV-specific parts are put together in a separate “sub-line.”

“Right now, about one in every seven cars is a Leaf, and we’ll start building more until we reach maximum capacity in March,” Honda said.

Nissan has taken orders for 6,000 Leafs in Japan and 20,000 in the United States so far, closing reservations for the time being. It sold the first Leafs in Portugal this month and will begin deliveries in select European markets in the coming months.

Nissan Americas Chief Carlos Tavares said earlier this month the automaker has committed to delivering the Leaf to all 20,000 U.S. customers by September.

Nissan and Renault are preparing factories around the world to manufacture a combined 500,000 lithium-ion batteries a year, mainly for their electric vehicles, by 2015.

The companies’ joint CEO, Carlos Ghosn, has predicted that one-tenth of all new vehicles sold worldwide would be all-electric by 2020, and wants the alliance to take the biggest share, much as Toyota Motor Corp has done with gasoline-electric hybrids.