BEIJING, May 22 (Reuters) - China's sugar futures tumbled into negative territory and dropped more than 1 percent as traders said the government's decision to slap hefty import duties on sweetener was too lenient to stem the flow of sugar into the world's top importer.
* At 0259 GMT, the most-active futures were down 0.73 percent at 6,672 yuan ($968.43) per tonne.
* The ruling was inline with a draft proposal issued in April, which many traders said was too low to stop the hefty flow of foreign arrivals that has damaged the domestic industry.
* Beijing will levy an extra 45-percent duty on top of the current 50 percent duty for out-of-quota sugar imports for this fiscal year, China's Commerce Ministry said in a statement. The duty will be eased to 40 percent in the following year and 35 percent a year later.
* Beijing included a list of almost 200 countries, including Myanmar, which is a major gateway for smuggling into China, which will be excluded from the new duties.
* One trader in China said the vast list of countries excluded from the ruling reduced its significance. ($1 = 6.8895 Chinese yuan renminbi) (Reporting by Josephine Mason)