BEIJING -- China's 21 major securities brokers convened on Saturday, vowing to "firmly" stabilize the country's stock market, which is suffering from continued plunges.

The Securities Association of China said in a statement that it appreciated the brokers' decision and asked all broker firms to view China's economic situation and capital market in a correct way and take concrete actions to underpin the ailing market.

The 21 brokers will spend no less than 120 billion yuan ($19.62 billion) on blue chip-based exchange traded funds (ETF), accounting for 15 percent of their total net assets, according to a joint statement issued by the brokers.

The brokers will not sell the stocks they held on July 3 and buy more in a proper time so long as the benchmark Shanghai Composite Index is below 4,500 points.

The Securities Association of China said in a statement that it appreciated the brokers' decision and asked all broker firms to view China's economic situation and capital market in a correct way and take similar actions to underpin the ailing market.