BEIJING?-- Lock-up shares worth 19.4 billion yuan ($3.14 billion) will become tradable on China's stock market this week, according to data from the country's two bourses.

A total of 4.38 billion non-tradable shares from 20 listed companies on the Shanghai and Shenzhen stock exchanges will be open for trade after their lock-up agreements expire this week.

Under China's market rules, major shareholders of non-tradable stocks are subject to one or two years of lock-up period before they are allowed to trade the shares.

GD Power Development Co Ltd,?a Beijing-based power company, will see 1.44 billion locked-up shares worth 3.28 billion yuan become tradable on Monday. This will be the largest amount to become tradable in Shanghai this week.

Of the 20 companies, 12 will see shares unlocked on Monday, with their combined value accounting for 57.21 percent of the total value of unlocked shares this week.