UPDATE 1-China Sept sugar imports slide by two-thirds as tariffs bite

* Sept sugar imports drop 67.5 pct on year to 160,000 t

* Jan-Sept sugar imports down 29.8 pct to 1.83 mln t

* But Sept corn imports rocket on temporary tight supply (Adding details and background)

BEIJING, Oct 23 (Reuters) - China's sugar imports in September fell two-thirds from a year earlier as hefty tariffs on foreign arrivals continued to dent buying appetite, customs data showed on Monday, while corn imports surged to meet temporary tightness in supply.

Last month's sugar imports <SU-CN-IMP> slumped 67.5 percent to 160,000 tonnes, data from the General Administration of Customs showed. Imports in the first nine months of the year fell 29.8 percent from a year earlier to 1.83 million tonnes.

Beijing has slashed permits for out-of-quota sugar imports to around 1 million tonnes, almost half of last year's allowance. It also imposed extra tariffs on sugar imports after lobbying by domestic mills, all part of its efforts to curb imports that it says have damaged the domestic industry.

That led imports in July to just 60,000 tonnes, the lowest in three years. September imports were also down 20 percent from the previous month's 200,000 tonnes.

Meanwhile corn imports <CO-CN-IMP> in September were up over 13-fold on the year, at 250,000 tonnes, as buyers snapped up grain from overseas amid temporary tightness in supply at home.

They were down 33.7 percent from the prior month's 377,518 tonnes, the data showed.

China bought 2.28 million tonnes of corn in the first nine months of the year, up 23.6 percent from a year earlier, according to the data.

Imports of the grain, used to feed China's huge livestock sector, plunged in the second half of last year, after domestic supplies became much cheaper following an overhaul in farm policy.

But overseas purchases have recovered in recent months, with Chinese prices relatively high for much of this year amid healthy demand for animal feed and industrial processing.

Concerns that drought would impact the quality of the crop and delay harvesting also pushed up local prices in August and September. (Reporting by Hallie Gu and Dominique Patton; Editing by Subhranshu Sahu and Kenneth Maxwell)