BEIJING - Chinese shares fell slightly on Tuesday amid growing concerns over the eurozone debt crisis after Moody's Investors Service lowered credit ratings on six European nations on Monday.

The benchmark Shanghai Composite Index was down 0.3 percent, or 7.08 points, to finish at 2,344.77.

The Shenzhen Component Index lost 0.43 percent, or 41.3 points, to end at 9,543.77.

Combined turnover of the two bourses narrowed to 130.3 billion yuan ($20.7 billion) on Tuesday from 153.2 billion yuan the previous trading day.

Losers outnumbered gainers by 499 to 393 in Shanghai, and by 758 to 597 in Shenzhen, with 168 shares remaining unchanged on the two markets.

Moody's cut its ratings on Italy, Spain and other four European countries on Monday, citing their susceptibility to the growing financial and macroeconomic risks caused by the eurozone crisis.

Construction and financial sectors led the decline, with Sinoma International Engineering Co., Ltd. losing 0.55 percent to 17.94 yuan and China Pacific Insurance (Group) Co., Ltd. down 2.71 percent to 20.83 yuan.

Banks took a blow from the news that China's national social security fund has reduced its holdings of Hong Kong-listed Chinese bank shares.

The National Council for Social Security Fund has cashed in a total of HK$153 million ($20 million) by cutting its H-share holdings of the Industrial and Commercial Bank of China (ICBC) and the Bank of China (BOC), according to a document submitted to the Hong Kong Stock Exchange on Monday.

ICBC shares in Shanghai dropped 0.46 percent to 4.35 yuan, while BOC shares declined 0.33 percent to 3.02 yuan in Shanghai.