(Adds china data, quotes, updates prices)
SYDNEY, May 8 (Reuters) - Copper retreated in Asian trade to the lowest prices in four months, with high inventories weighing on prices in both London and Shanghai markets, amid a sharp drop in imports to China.
Chinese imports of unwrought copper and concentrates fell in April from the previous month, customs data showed on Monday, as demand from the top consumer and producer of the metal eased amid a subdued outlook for industrial activity.
April imports of copper dived 30.2 percent from a month ago to 300,000 tonnes, data from the General Administration of Customs showed, and they were down by a third from a year ago.
"It's clear that suppliers have been stocking up on copper and putting it into inventory," said Amy Li, an economist for National Australia Bank.
"We are still forecasting a slowdown in the Chinese residential sector, so that means lower demand for base metals, including copper," she said.
"It was mainly due to weak domestic demand and also that China's output remained strong, so the country didn't need to import as much," said Helen Lau, an analyst at Argonaut Securities in Hong Kong.
* LONDON COPPER: Three-month copper on the London Metal Exchange was down 1.7 percent to $5,490 a tonne at 0751 GMT. The contract dropped as low as $5,482.75 a tonne, the lowest since Jan. 4, Reuters data showed.
* SHANGHAI COPPER: The most-traded copper contract on the Shanghai Futures Exchange fell 0.7 percent to 44,670 yuan ($6,471) a tonne.
* LME STOCKS: Inventories in London Metal Exchange (LME) warehouses climbed by 36,800 tonnes, exchange data showed on Friday, bringing last week's surge to 40 percent.
CHINA METALS: Copper concentrate and ore imports dropped 16.6 percent from a month earlier to 1.36 million, though that marked a 7.9 percent increase from a year earlier.
Three month LME copper
Most active ShFE copper
Three month LME aluminum
Most active ShFE aluminum
Three month LME zinc
Most active ShFE zinc
Three month LME lead
Most active ShFE lead
Three month LME nickel
Most active ShFE nickel
Three month LME tin
Most active ShFE tin
ARBS ($1 = 6.9031 Chinese yuan)
(Reporting by James Regan; Editing by Joseph Radford and Sherry Jacob-Phillips)