Lock-up shares worth 24.1 billion yuan (3.94 billion U.S. dollars) will become eligible for trading this week in China, according to data from the country's two bourses.

The volume is a decline from the 27.3 billion yuan worth of shares that became tradable last week, [company registration in Hong Kong, Hong Kong company incorporation]according to the Shanghai and Shenzhen stock exchanges.

Altogether, the lock-up shares to be released to the capital market after agreements expire are from 18 companies, including four listed in Shanghai and 14 in Shenzhen.

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 their shares.