BEIJING, Aug 21 (Reuters) - China's leading flash memory chipmaker YMTC plans to raise 33 billion yuan ($4.91 billion) in its Shanghai IPO, an updated prospectus filed to the stock exchange showed on Friday.
($1 = 6.7205 Chinese yuan renminbi)
(Reporting by Yukun Zhang, Shi Bu and Ryan Woo; Editing by Sharon Singleton)