BEIJING, July 31 -- Lock-up shares worth over 17 billion yuan (about 2.56 billion U.S. dollars) will become eligible for trade on the Shanghai and Shenzhen bourses in the coming week.

The value is lower than the previous week's 21.6 billion yuan, according to RoyalFlush Information.

The lion's share of the new shares belongs to Shenzhen O-film Tech Company, with more than 209.45 million non-tradable shares worth 6.73 billion yuan to be unlocked Wednesday.

Other listed firms that will see large quantities of lock-up shares turn tradable include Zhejiang Crystal-optech Company, a producer of optoelectronic parts, and software developer Beijing BDStar Navigation Company.

Under China's market rules, major shareholders of non-tradable stocks are subject to one or two years of lock-up before they are permitted to sell these stocks.

Chinese stocks closed lower on Friday, with the benchmark Shanghai Composite Index down 0.5 percent, closing at 2,979.34 points.