As part of the taxi industry's move away from diesel, cab giant ComfortDelGro Corp will buy up to 1,200 petrol-electric Hyundai Ioniq Hybrids, which will be delivered by the middle of next year.

The dominant taxi operator started taking delivery of the first batch of 200 cabs in the second quarter of this year, and called a tender in May for 500 more.

The latest deal includes an option for an additional 500, which, if all goes well, will be delivered by the middle of next year, according to a spokesman for Hyundai agent Komoco.

"The taxi industry has shown signs of stabilising and we have started to place orders for new taxis given growing demand from hirers old and new," ComfortDelGro spokesman Tammy Tan said yesterday.

ComfortDelGro has been buying taxis from Hyundai - mostly Sonatas and i40 models - for a decade now. With a fleet size of about 12,500, its taxis make up 59 per cent of Singapore's cab population.

Last week, ComfortDelGro put two fully electric Hyundai cabs on the road.

Up till recently, most cabs in the Republic have been diesel-powered. But with emission standards becoming more stringent, operators have started steering away from diesel.

According to Land Transport Authority figures, there were 4,159 petrol-electric hybrid taxis on the road as at the end of June. These cabs now account for 20 per cent of Singapore's taxi fleet of around 21,000.

Just five years ago, there were only 662 hybrid cabs here, which made up 2.4 per cent of the taxi population.

In comparison, the penetration rate for passenger cars is far lower, with less than 4 per cent of the population being partly or fully electric.

Elsewhere, Trans-Cab, the second-largest operator here, has ordered 500 petrol-electric Toyota Prius cabs. The vehicles will start plying from October.

Observers said since taxis clock at least three times as many kilometres as the average family car, the benefit of converting them to less pollutive models is multiplied.