China markets tumble despite beefed-up support measures; HK down 1.2 pct
* CSI300 -4.4 pct; SSEC -3.2 pct; HSI -1.2 pct
* Support measures not enough to stem market slide - analysts
* Over 200 companies suspend share trading on Tuesday
SHANGHAI, July 7 (Reuters) - Chinese stocks plummeted yet again on Tuesday morning, defying rapid-fire emergency support measures from Beijing and raising concerns about policy makers' ability to stabilise one of the most highly volatile markets in the world.
Some high-profile announcements by state-backed investors that they are putting money into the market did little to assuage sentiment, with many investors forced to sell to meet margin calls.
The CSI300 index tracking China's biggest companies opened down 3 percent and ended the morning 4.4 percent lower, turning Monday's gain into a blip in a three-week long downward trend. The CSI extended losses when it reopened for afternoon trade.
The Shanghai Composite also wiped out previous session's gains and tumbled 3.2 percent by midday, despite signs of heavy money inflows into Shanghai-listed blue chips.
Shenzhen's tech-heavy growth board ChiNext took a bigger hit, tumbling 5.1 percent, while the Shenzhen Composite dived 5.9 percent, reflecting extreme weakness in small caps.
The resumption of the selloff comes despite unprecedented emergency rescue measures announced over the weekend, which included a pause in initial public offerings and a pledge by the central bank to provide liquidity support to the market. Continuación...