REFILE-China stocks rout on first market day of 2016 trips national trading halt
(Adds dropped word "prior" in the fourth to last paragraph)
* Chinese major CSI300 index drops 7 pct before "circuit breaker" halts trade
* Worst trading day since stock crash in Aug 2015
* Investors reacting to weak econ data, end of share lockup period
* Circuit-breaker seen by some as emboldening market bears
By Pete Sweeney and Samuel Shen
SHANGHAI, Jan 4 (Reuters) - China's major stock exchanges tanked on the first trading day of the year, triggering a "circuit-breaker" that suspended equities trade nation-wide for the first time and put months of regulatory work to restore market stability at risk.
The selloff saw the CSI300 index of the largest listed companies in Shanghai and Shenzhen lose 7.0 percent before trading was suspended, its worst single-day performance since late August 2015, the depth of a summer stock market rout.
The collapse, which followed the release of weak economic data on Monday, raises fresh doubts about regulators' capacity to wind back heavy trading restrictions implemented in the wake of a massive summer stock crash in which major indexes lost as much as 40 percent before top leadership intervened. Continuación...