METALS-Caution over U.S.-China trade truce drags on copper

* China copper premiums at 18-month low

* GRAPHIC-2018 asset returns: (Updates with official prices)

LONDON, Dec 4 (Reuters) - Copper eased on Tuesday as markets awaited remedial action by the United States and China after the two countries' weekend agreement on a 90-day ceasefire in their damaging trade dispute. Other metals, however, clung on to the previous session's gains, powered by a weaker dollar. At the G20 summit this weekend, Washington and Beijing agreed to hold off on further tariffs for 90 days, pausing a dispute that had dragged down metals and equity markets.

Markets remain sceptical, however, that full resolution will be achieved soon.

"The G20 has always been long on rhetoric and short on substance, so now we need to see some instant action taking place," said Societe Generale metals specialist Robin Bhar.

The United States expects China to cut tariffs on U.S. car imports and end intellectual property theft and forced technology transfers as the countries move towards a broader trade deal, a White House official said on Monday.

Three-month benchmark copper on the London Metal Exchange (LME) was bid 0.3 percent lower at $6,277 a tonne after failing to trade in official rings. The metal gained 1.6 percent on Monday.

METALS FLOOR: "Initial G20 euphoria soon gave way to the realisation that nothing has actually been resolved," Brokerage Marex Spectron said in a note. "Weekend events probably raise the floor to the (metals) complex, although whether that leads us to some sort of new panacea is highly debatable."

COPPER PREMIUMS: The premium for copper imports into China, the world's biggest copper consumer, sank to an 18-month low on Monday in a sign that demand for physical metal is waning after a buying spree.

TECK: Canadian mining company Teck Resources, has agreed to sell a 30 percent stake in its Quebrada Blanca copper mine expansion in northern Chile to Japan's Sumitomo for $1.2 billion.

ALUMINIUM: A Japanese aluminium buyer has agreed to pay a global producer a premium of $85 a tonne over the benchmark price for shipments in January to March, the lowest in more than two years, two sources involved in pricing talks said on Tuesday.

PRICES: Aluminium added 0.4 percent to $1,980 a tonne, zinc rose 1 percent to $2,610, lead was up 1 percent at $1,984, tin was bid up 1.3 percent to $19,075 and nickel was bid up 0.6 percent to $11,350.

(Additional reporting by Tom Daly Editing by Ed Osmond and David Goodman)