BEIJING -- Lock-up shares worth 40.3 billion yuan ($6.61 billion) will become eligible for trading this week in China, according to data from the country's bourses.

The volume marks an increase from the 29.3 billion yuan seen from October 28 to November 1.

Altogether, 23 listed companies on the Shanghai and Shenzhen stock exchanges will see their lock-up shares released to the capital market after the lock-up agreements expire.

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 the shares.

Rongsheng Petrochemical Co, Jointown Pharmaceutical Group Co and Henan Dayou Energy Co will see non-tradable shares worth 8.4 billion yuan, 7.4 billion yuan and 6.8 billion yuan respectively eligible for trade this week.