UPDATE 1-China property investment growth cools in Oct, sales decline accelerates

accelerates@ (Adds detail)

* Oct property investment growth slows to +5.6 pct - Reuters calculation

* Oct property sales -6.0 pct

BEIJING, Nov 14 (Reuters) - Real estate investment cooled in October and a sales decline steepened, reinforcing expectations of a gradual slowdown in China's economy as the property sector loses momentum amid official crackdown on riskier lending.

Real estate, which directly affects 40 other business sectors in China, is a crucial driver for the economy but also poses a major risk as Beijing looks to tame soaring home prices without triggering a crash.

Property investment grew 5.6 percent in October from a year earlier, cooling from expansion of 9.2 percent in September, according to Reuters calculations based on data from the National Bureau of Statistics on Tuesday. October's growth was the slowest since July.

Investment in the first 10 months of the year rose 7.8 percent from a year earlier, compared with 8.1 percent in Jan-Sept. The figure mainly focuses on residential real estate but also includes commercial and office space.

China's economy has surprised global financial markets and investors with robust growth of 6.9 percent so far this year, driven by a renaissance in long-ailing "smokestack" industries such as steel.

Property sales by floor area fell by 6.0 percent in October from a year earlier, compared with a 1.5 percent decline in September, according to Reuters calculations. The decline was the biggest since the first two months of 2015.

New construction starts measured by floor area, a telling indicator of developers' confidence, were down 4.3 percent in October from a year earlier, after only rising 1.4 percent in September, Reuters calculations showed.

Home prices in the biggest cities have softened slightly and gains in smaller cities have slowed in response to cooling measures, though there have been no hints of a crash which could destabilise the economy or stir social unrest.

Household loans, mostly mortgages, fell to 450 billion yuan in October from 735 billion yuan in September, Reuters calculated from central bank data out on Monday.

Chinese authorities have intensified efforts to curb illegal financing for mortgage down payments and have asked banks to step up checks on home buyers' income authenticity, the official Xinhua news agency reported in early November.

China's housing market has been on a near two-year tear, giving the economy a major boost but stirring fears of a property bubble even as the authorities try to contain risks from a rapid build-up in debt.

The head of the central bank warned in October that China's household debt was rising too quickly, and some analysts suspect a recent burst of consumer lending points to the illicit use of loans for property investment.

China's outstanding household consumer loans surged nearly 30 percent by end September from a year earlier, data showed.

Taming the overheated property market has been a top priority for China's policymakers this year as they looked to ensure social stability and reduce risks to the financial system as China shifted to focus more on high-quality growth in its economy. (Reporting by Stella Qiu and Kevin Yao; Writing by Elias Glenn; Editing by Eric Meijer)