Swiss May platinum imports from SAfrica hit 26-mth low

* Overall Swiss platinum, palladium imports rise in May

* Imports of raw, powdered palladium from Russia nil for second month

LONDON, June 21 (Reuters) - Monthly Swiss imports of raw and powdered platinum from South Africa, source of nearly four out of five ounces of world supply of the white metal, fell to their lowest in more than two years in May, Swiss customs data showed on Thursday.

The republic exported 247 kilograms of the autocatalyst metal to Switzerland, a major refining and trading hub, last month, down from 339 kg in April and the lowest since the 217 kg recorded in March 2010.

South African platinum miners have been hit by a wave of problems this year, with rising costs, falling metals prices and a wave of industrial unrest all cutting into margins.

Aquarius Platinum, the world's fourth-largest producer of the white metal, said on Wednesday it was putting its Everest mine on care and maintenance.

Overall platinum imports into Switzerland recovered from April's four-year low to reach 1.398 tonnes in May, up from 949 kg the previous month, though that was still the second lowest monthly total this year. Its palladium imports rose to 1.516 tonnes from 926 kg.

Russian palladium exports to Switzerland in raw and powdered form were nil for a second consecutive month, though it exported 201 kg of semi-processed metal.

Sales of surplus material from Russian government stockpiles have been a swing factor in recent years in determining the balance of supply and demand in the palladium market.

Sales are expected to dwindle to around 250,000 ounces this year from over 1 million ounces in previous years, according to refiner Johnson Matthey.

Swiss platinum exports to China, the largest platinum jewellery market, jumped by more than two-thirds month-on-month in May to 1,553 kilograms, while exports to Hong Kong also rose 17 percent.

China and Hong Kong were the destination of around 90 percent of Swiss platinum exports in raw or powdered form last month, the data showed.

Exports of palladium to Hong Kong fell to 199 kilograms in May from 1,621 kilograms in April, while China's palladium imports from Switzerland remained at nil for a second month.

The UK was the main destination of Swiss raw and powdered palladium exports, taking 5 tonnes of material, up from 16 kilograms last month.

Platinum and palladium are used in industrial applications, predominantly in catalytic converters to cut vehicle emissions and depend greatly on the health of the U.S., Chinese and European regional economies for demand. (Reporting by Jan Harvey; editing by James Jukwey)