* China Sept vehicle sales +5.7 pct, YTD +4.5 pct
* Fourth consecutive month of rising sales
* China may not hit 5 pct annual growth forecast- industry body
* NEV Sept sales +79.1 pct, set to hit annual target (Adds details on new full-year target, new energy vehicle sales)
BEIJING, Oct 12 (Reuters) - China's vehicles sales rose in September for a fourth straight month, an industry body said on Thursday, but added that the market may struggle to hit a forecast for 5 percent annual growth set earlier in the year.
The world's largest auto market may not hit growth levels estimated by the China Association of Automobile Manufacturers in January, "but 4 percent and above should be pretty much a sure thing", said Shi Jianhua, CAAM's deputy secretary general.
Vehicle sales in China have rebounded since June, but CAAM's caution on full-year growth underlines challenges in the market, which saw a slow start to the year due to tax incentives on smaller-engined cars being phased out.
China vehicle sales touched 2.71 million units in September, up 5.7 percent from a year ago, CAAM data showed.
That took year-to-date sales to 20.2 million vehicles, up 4.5 percent against the same period in 2016. Vehicle sales in the country rose 13.7 percent last year.
Recent sales have been relatively strong - growing 5.3 percent in August, 6.2 percent in July and 4.5 percent in June - underpinned by stronger overall economic growth and increased incentives for buyers, market watchers said.
Most global carmakers are seeing positive sales in China: Japan's Toyota Motor Corp, Honda Motor Co, Nissan Motor Co Ltd and U.S. carmaker General Motors posted higher growth this week.
Ford Motor Co, set to report September sales later this week, has lagged its global peers in China this year.
CAAM data showed sales of new energy vehicles (NEV) shot up 79.1 percent in September amid a government push to support the sector and shift away from traditional petrol engine cars in the long term. NEV sales so far this year have totalled 398,000, up 37.7 percent against 2016.
China is expected to meet a sales target of 700,000 NEV units this year, CAAM official Chen Shihua said at a briefing in Beijing, referring to all-electric battery vehicles as well as plug-in petrol-electric hybrids.
The country has set strict quotas for NEVs which carmakers must meet by 2019, a move that is prompting a flurry of electric car deals and new launches of electric and hybrid models as firms look to ensure they do not fall short. (Reporting By Norihiko Shirouzu and Cheng Fang, Writing by Adam Jourdan; Editing by Himani Sarkar)