Copper prices retreated on Tuesday on persistent worries about the health of the Chinese economy and metals demand after fresh data.

Three-month copper on the London Metal Exchange (LME) eased by 0.4% to $9,063.50 a metric ton in official open-outcry trading, having gained 1.1% in the previous session.

Data on Tuesday added to a string of recent weak numbers, with China's unwrought copper imports sliding to a 16-month low in August and total imports missing expectations, reflecting weak demand.

"The economic story in China is definitely weak, consumers are depressed and there's this massive overhang of unsold property," said Dan Smith, head of research at Amalgamated Metal Trading.

A trader in Asia expected copper to fall to $8,450 a ton.

Smith, however, said the picture was not all gloomy.

"Overall, we shouldn't be too pessimistic about the outlook for base metals. The electronics side of things and solar PV are doing quite well in China," he said, referring to photovoltaic (PV) technology used in solar panels.

Demand was growing at an average of 16% in six electronics business sectors in China up to July, Smith added.

He expects copper to rise moderately in the coming months and end the year at about $9,500 a ton.

Another positive signal was a rise in the premium to import copper into China to $65 a ton, its strongest in more than eight months.

The most traded October copper contract on the Shanghai Futures Exchange (SHFE) closed 1.4% up at 73,110 yuan ($10,268.40) a ton, tracking overnight gains in London.

In other metals, LME aluminium slipped 0.3% to $2,343 a ton, nickel was down 0.5% at $15,825 and zinc dropped 1.2% to $2,698 while tin lost 0.2% to $30,750 and lead added 0.1% to $1,955.

 ($1 = 7.1199 yuan)

(Reporting by Eric Onstad Additional reporting by Mai Nguyen in Hanoi Editing by David Goodman)