(Reuters) - Global sales of fully electric and plug-in hybrid vehicles grew 15% in August from a year ago, marking the slowest rate since January and reflecting tougher comparatives, market research firm Rho Motion said on Friday.

China's EV sales growth, which averaged 36% a month in the first half, cooled to 6% in August. However, China sales are still expected to be strong in the fourth quarter as new funds become available for its subsidy schemes and the usual seasonal rebound, said Rho Motion data manager Charles Lester.

WHY IT'S IMPORTANT

China is the world's biggest car market and accounts for more than half of global EV sales, which in Rho Motion's data include battery-electric vehicles and plug-in hybrids.

China's overall car sales growth slowed to the weakest in seven months in August. China's BYD, the world's largest EV maker, last week cut its 2025 global sales target by as much as 16%.

However, August was the best month yet in terms of EV and hybrid sales for Geely, Xpeng ( XPEV ) and Nio, underscoring how smaller local rivals are picking up market share in China.

Growth in other markets has partially made up for the China weakness. U.S. demand has surged ahead of expiring tax credits and Europe has seen momentum from incentives aimed at speeding up decarbonisation.

BY THE NUMBERS

Global sales of battery-electric vehicles and plug-in hybrids rose to 1.7 million units in August, Rho Motion data showed. The same month last year had benefited from subsidy-boosted demand in China.

The rate of growth was down from 21% in July.

Chinese sales reached 1.1 million vehicles. European sales rose 48% to about 283,453 units, while North American sales climbed 13% to 201,255. Sales in the rest of the world jumped 56% to more than 144,280 vehicles.

KEY QUOTE

"In the US, we're expecting record sales in August and then another strong month in September; it could be another record and then likely a big drop," Lester said.

"BYD still has the market share, and they're certainly now feeling the pressure from other OEMs," he added.