BEIJING, May 22 (Xinhua) -- Chinese shares closed mixed Tuesday as major indices turned lackluster after a two-day gaining streak.

Both main board indices opened lower. The benchmark Shanghai Composite Index ended higher, but only with a slight increase of 0.02 percent to hit 3,214.35 points. The Shenzhen Component Index closed flat at 10,765.81 points.

Combined turnover on the two bourses went down to 438.2 billion yuan (about 68.68 billion U.S. dollars) from 461.2 billion yuan on the previous trading day.

Shares related to childcare, pork and natural gas posted strong performance. Muyuan foods Co., Ltd. in feed processing and pig husbandry jumped 5.49 percent to 53.44 yuan per share, and Shaanxi Provincial Natural Gas Co., Ltd. climbed 5.2 percent to 8.3 yuan per share.

The financial and steel sectors were among the biggest losers. The sub-index for the financial sector shed 1.01 percent.

Bucking the trend of the main board, the ChiNext Index, which tracks China's NASDAQ-style board of growth enterprises, went up 0.73 percent to close at 1,876 points Tuesday.