* GRAPHIC-2019 asset returns: http://tmsnrt.rs/2jvdmXl (Updates with closing prices)
LONDON, Dec 16 (Reuters) - Copper prices rose on Monday on optimism that a China-U.S. trade deal would help boost economic growth and demand for metals, but some analysts doubted new highs would be hit before next year.
U.S. President Donald Trump's top trade negotiator praised a "phase one" U.S.-China trade deal expected to nearly double U.S. exports to China over the next two years, while China remained cautious ahead of the signing of the agreement.
"Copper needs to show that these levels are justified. The cat is out of the bag, the deal is done, now comes the hard slog to actually deliver," said Ole Hansen, head of commodity strategy at Saxo Bank in Copenhagen.
"The market may want to adopt a wait-and-see approach until we get some hard data that really confirms that both sides are living up to the deal. Potentially, copper may move back just to check the proper level of support."
Copper broke above $6,200 a tonne for the first time in seven months on Friday before ending lower. It had gained 7% in little over a week on hopes for a trade deal, worries about supply in top producer Chile and brighter economic data.
Three-month copper on the London Metal Exchange gained 1.1% to $6,199 a tonne in final open-outcry trading, after ending down 0.4% on Friday.
* CHINESE DATA: Growth in China's industrial and retail sectors beat expectations in November, data showed on Monday, as government support propped up demand in the world's second-largest economy.
"November activities rebounded, and we believe the momentum will likely continue towards year-end," Citi analyst Li-Gang Liu said in a note, adding that the bank expects economic growth of 6.1% in the fourth quarter and 6.2% for the whole year.
* ALUMINIUM OUTPUT: China's aluminum production rose 0.6% in November from the previous month to 2.9 million tonnes, official data showed on Monday, as some top producers were exempted from winter output restrictions.
* ALUMINIUM STOCKS: On-warrant aluminum inventories - material not earmarked for delivery - in LME-approved warehouses climbed by 45,075 tonnes to 1,309,000, the highest since February 2017, daily LME data showed on Monday
LME aluminum gained 0.6% to end at $1,778 a tonne.
* NICKEL: Indonesia, the world's largest nickel ore exporter, exported 2.7 million tonnes of nickel ore worth $112.05 million in November, data showed on Monday.
* PRICES: LME zinc climbed 1.7% in closing rings to $2,291 a tonne, nickel rose 0.2% to $14,200, lead slipped 1.2% to $1,887.50 and tin lost 0.3% to $17,175. (Additional reporting by Tom Daly in Beijing; Editing by Kirsten Donovan/David Evans)