NEW YORK (AP) â¿¿ Shares of some Chinese companies trading on U.S. stock exchanges fell Friday after a report showed that China's manufacturing activity was stagnant in September. HSBC said its purchasing managers index for September was flat at 49.9. Although it was higher than the 49.4 expected, the reading was still below 50, which indicates that activity is contracting. It's the third straight month that the index has been below 50. "Some analysts have significantly revised down their growth expectations for China, which is starting to spook investors," said Forex.com analyst Kathleen Brooks. Chinese stocks also took a hit on Thursday, after news agency Reuters reported that the U.S. Justice Department was reviewing accounting irregularities at U.S.-listed Chinese companies. In afternoon trading Friday, shares of BNY Mellon China Select ADR â¿¿ an index that tracks Chinese stocks â¿¿ were down nearly 2 percent. Shares of some individual Chinese companies that trade in the U.S. also fell: â¿¿ Oil and gas producer China Petroleum & Chemical Corp. fell $1.54 to $96.20. Social networking company Renren Inc. fell 57 cents, or 9.7 percent, to $5.28. â¿¿ Trina Solar Ltd. fell 26 cents, or 4.1 percent, to $6.14. â¿¿ Entertainment media company Shanda Interactive Entertainment Ltd. fell $1.51, or 4.9 percent, to $29.57. â¿¿ Internet technology NetEase.com Inc. fell 33 cents to $38.63. â¿¿ Online retailer E-Commerce China Dangdang Inc. fell 16 cents, or 3.1 percent, to $5.08. â¿¿ Coal producer Yanzhou Coal Mining Co. Ltd. fell $1.15, or 5.1 percent, to $21.60. Asian stock indexes also fell Friday: â¿¿ Mainland China's Shanghai Composite Index closed down 0.3 percent. â¿¿ Hong Kong's Hang Seng fell 2.3 percent. â¿¿ Japan's Nikkei 225 fell 0.01 percent.