Commercial property sales in China's booming Zhejiang province fell sharply in 2011 following tough government curbs.

The total floor space sold slumped 20.5 percent year-on-year to 38.3 million square meters last year, the provincial statistics bureau said in a statement Wednesday.

Sales declines quickened with each quarter passing. The decline for the whole year was 15, 12.1 and 5.2 percentage points higher than that in the first quarter, first half and first three quarters, respectively, it said.

Of all, commercial housing sales fell 21.6 percent last year in terms of floor area, the statement indicated.

China's once red-hot property sector showed signs of cooling off last year with the help of tough government measures, including higher mortgage rates, a ban on third-home mortgage loans and purchase restrictions.

Several major Chinese cities, such as Beijing, Shanghai and Guangzhou, also have reported sagging real estate sales last year following the tough regulatory measures

China will unswervingly maintain its regulation policies on the property market in 2012, which are intended to return housing prices to a reasonable level, according to decisions made at the country's annual central economic work conference last December.

With no signs of immediate loosening of tightening measures and thus gloomy prospects, many cash-strapped property developers rolled out big discounts to promote sales as they struggled to pay back debts at the end of last year, the bureau said.

Earlier several local developers in Zhejiang were reported to be in a liquidity crisis or unable to pay back debts, and many real estate agencies have closed stores due to declining housing sales.