BEIJING - Lock-up shares worth around 62 billion yuan ($9.7 billion) will become eligible for trade on China's stock market?this week.

About 7.75 billion shares from 20 companies will become tradable on the Shanghai and Shenzhen bourses, data from Southwest Securities showed. The volume was up from the 45 billion yuan of shares unlocked this week.

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 trade.

Bank of Communications will see non-tradable shares worth around 40 billion yuan become tradable on the Shanghai Stock Exchange on Aug 24, the largest amount to hit the market next week.

China's stock markets continued to decline beset by shrinking turnover and greater volatility. The key Shanghai index plunged 4.3 percent on Friday following the release of weak economic data. It has declined more than 30 percent from its June peak, wiping out most of this year's gains.