BEIJING -- Lock-up shares worth 18.3 billion yuan ($2.97 billion) will become eligible for trading this week in China, according to data from the country's bourses.

The volume marked a decline from the 24.1 billion yuan worth of shares that became tradable last week, according to the Shanghai and Shenzhen stock exchanges.

Altogether, 2.2 billion lock-up shares of 25 listed companies will be released to the capital market after agreements expire, accounting for 0.53 percent of the total lock-up A-shares.

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.