BEIJING - Lock-up shares worth about 16.6 billion yuan ($2.5 billion ) will become eligible for trade on the Shanghai and Shenzhen stock exchanges in the coming week.

The volume increased moderately from 12.7 billion yuan in the past week, according to RoyalFlush Information, a financial information service company. About 1.23 billion shares from 24 companies will become tradable from September 12 to 14.

Hunan Jiangnan Red Arrow Co, an internal-combustion engine component supplier, will see the unlocking of 574 million shares worth about 7.65 billion yuan, the largest group of locked-up shares to hit the market.

Under China's market rules, major shareholders of non-tradable stocks are subject to a one or two year lock-up before they are permitted to sell.

China stocks closed lower on Friday with the benchmark Shanghai Composite Index down 0.55 percent to close at 3,078.85 points.