BEIJING, March 12 (Reuters) - London base metals gained ground on Tuesday, with copper rising by the most in a week, as a softer dollar and improving investor sentiment after changes to a Brexit deal lent support to prices. A weaker greenback makes dollar-denominated metals cheaper for holders of other currencies. "The overall market sentiment is heating up," said Xu Maili, head of non-ferrous metals research at Everbright Futures in Shanghai. This is also reflected in gains in the ferrous complex, equities and crude oil prices, he added. Xu remains bullish on copper in the medium term even after an 8.4 percent gain for the metal so far this year, with possible fluctuations due to profit-taking, he said in a note. "Furthermore, it will take time for the rising copper prices to be accepted by the downstream industry," Xu added. FUNDAMENTALS * COPPER: Three-month copper on the London Metal Exchange rose as much as 1 percent, the most since March 5, and was up 0.9 percent at $6,464 a tonne, as of 0447 GMT. The most-traded May copper contract on the Shanghai Futures Exchange added 0.7 percent to 49,360 yuan ($7,353.55) a tonne. * COPPER: Production at Chinese miner MMG Ltd's Las Bambas copper deposit in Peru could fall "in the near-term" due to a month-long road blockade by a community that was relocated to build the mine, the company said. * European Commission head Jean-Claude Juncker said on Monday he agreed an updated Brexit deal with British Prime Minister Theresa May to make the agreement more palatable to UK lawmakers but warned they would not get a third chance to endorse it. * TRADE: Chinese Vice Premier Liu He held a telephone call on Tuesday with U.S. Treasury Secretary Steven Mnuchin and U.S. Trade Representative Robert Lighthizer on key issues in their trade talks, state news agency Xinhua said. * U.S. DOLLAR: The dollar index fell 0.2 percent to 97.062 on a modest improvement in risk appetite. * OTHER METALS: Nickel was the biggest gainer in base metals on the LME, rising 1.5 percent to $13,090 a tonne, while aluminium added 1 percent and zinc, Monday's top performer, climbed another 1 percent. * ZINC: The global zinc market deficit narrowed to 28,000 tonnes in January from a revised deficit of 62,400 tonnes in December, data from the International Lead and Zinc Study Group showed. * ZINC: Zinc inventories in LME-approved warehouses at 59,450 tonnes are the lowest since October 2007. MZNSTX-TOTAL * ALUMINIUM: Queues to take aluminium out of LME-approved warehouses owned by ISTIM UK in Port Klang, Malaysia rose to 229 days in February from 118 days in January and zero days in December.