BEIJING, Jan 27(Reuters) - Profits earned by Chinese industrial firms in December fell 4.7 percent from a year earlier, the seventh straight month of declines, as the slowing economy hits sales and forces many companies to cut prices to win business.

Industrial profits - which cover large enterprises with annual revenue of more than 20 million yuan ($3.1 million) from their main operations - fell 2.3 percent in 2015 from 2014, the National Bureau of Statistics(NBS) said on its website on Wednesday.

That compared with 3.3 percent growth in 2014.

High costs and tight liquidity curbed companies' production and operations, along with weak domestic and global demand, the NBS said.

China's economic growth cooled to 6.9 percent in 2015, the slowest pace in a quarter of a century, weighed down by sluggish demand, industrial overcapacity, slowing investment and a struggling property market.

Producer prices fell for the 46th month in a row in December, highlighting the deeply entrenched pressures facing its manufacturers.

(Reporting by Beijing Monitoring Desk and Xiaoyi Shao; Editing by Kim Coghill)