Leo Zhang/Shanghai Daily

Concerns about weaker margins amid rising oil prices thrust Shanghai lower yesterday led by petrochemical firms.
The Shanghai Composite Index, which covers yuan-denominated A shares and foreign-currency B shares, withdrew 0.32 percent to 1,083.03. The A-share Index slid 0.33 percent to 1,138.69 while the B-share Index added 0.24 percent to 58.69.
"As the government still has a grip on the prices of petrochemical products, it's hard for them to pass on increasing raw material costs to consumers," Lu Chengde, a Guosen Securities Co trader said.
Crude oil for September delivery increased as much as 0.8 percent to US$60.41 a barrel in after-hours trading in New York. Oil futures are 41 percent higher from a year earlier.
China Petroleum & Chemical Corp, Asia's biggest oil refiner, dipped 0.49 percent to 4.08 yuan (50 US cents). Shanghai Petrochemical Co, the country's largest maker of ethylene, was down 1.93 percent to 3.55 yuan.
Sinopec Yizheng Chemical Fibre Co, China's No 1 chemical fiber producer, plunged 5.22 percent to 2.18 yuan.
Shanghai's key stock index climbed 3.5 percent this week as the government appreciated its currency by 2.1 percent against the US dollar.
"The key index may go beyond 1,100 next week on optimism that the value of yuan-denominated assets will rise," Guosen's Lu said.