BEIJING -- Lock-up shares worth 22.6 billion yuan ($3.66 billion) will begin tradable in Shanghai and Shenzhen stock exchanges this week, according to data from the two bourses.

Altogether, 17 listed companies on the Shanghai and Shenzhen stock exchanges will see their lock-up shares released to the equity markets after their lock-up periods become due in the week from August 5-9.

Under China's market rules, major shareholders of non-tradable stocks are prohibited from trading their shares during the lock-up periods, usually one or two years after the stock IPO, to protect retail investors.

Shenzhen O-film Tech Co Ltd, an optical component producer, will see non-tradable shares worth 5.2 billion yuan become tradable on Monday, the largest amount of such shares to hit the market in the week.