BEIJING/SHANGHAI, April 26(Reuters) - CITIC Securities Co , China's biggest brokerage, on Friday reported an 8.5% fall in first-quarter net profit.

Net profit fell to 4.96 billion yuan ($684.47 million) in the three months to March 31, compared with 5.42 billion yuan in the same period last year, the company said in a stock exchange filing. ($1 = 7.2465 Chinese yuan renminbi) (Reporting by Ziyi Tang and Engen Tham Editing by David Goodman )