MELBOURNE, March 26 (Reuters) - London metals extended their declines on Monday as concerns over U.S.-China trade relations continued to batter global stocks and threaten to blunt the demand for metals. U.S. President Donald Trump signed a memorandum on Friday that could impose tariffs on up to $60 billion of imports from China, although the measures have a 30-day consultation period before they take effect. "The announcement that President Trump would apply a 25 percent tariff on $50 billion of Chinese goods, including items in aerospace, information technology and machinery, continued to reverberate through the market," Australia's ANZ Bank said in a report. "China's response only strengthened the view that global economic growth could be affected by this escalation in trade tension." FUNDAMENTALS * LME COPPER: London Metal Exchange copper was down 1.3 percent at $6,575 a tonne, as of 0721 GMT, adding to losses from the previous session. Prices earlier dropped to $6,532 a tonne, their weakest since early December. * SHFE COPPER: Shanghai Futures Exchange copper dropped 2.5 percent to 49,000 yuan ($7,785.69) a tonne by close, hitting the lowest since July at 48,720 yuan. * Open interest in LME copper, a measure of activity in the global contract, fell to its lowest in more than two years last week. In Shanghai, however, open interest has jumped since mid-January to three-year highs, suggesting large short positions have been building in China. * "I am overall bearish everything," said a metals trader in Singapore, adding that copper was possibly facing a downside move after the break of some key chart levels. * LME copper closed below the 200-day moving average on Friday sending a "sell" signal to momentum following funds. * Other Shanghai metals slipped towards fresh multi-month lows. Shfe nickel dropped 3 percent at 9,6360 yuan a tonne by close, Shanghai aluminium slipped half a percent to a nearly 17-month trough, while Shanghai lead closed down 0.9 percent. * CHINA ECONOMY: China will steadily reform and further open its financial sector while putting "equal emphasis" on preventing risks through regulation and supervision, the new central bank governor said on Sunday. * SPECULATORS: Hedge funds and money managers cut their net long positions in COMEX gold and copper contracts in the week to March 20, the latest regulatory data showed. * DRC: Democratic Republic of Congo's mines minister rejected a proposal by mining companies on Friday to soften some provisions in a new mining code in exchange for higher royalties. * SMOG: Beijing and 33 other northern Chinese cities have issued smog alerts for the next few days as industrial output ramps up again after the end of winter restrictions, China's environment ministry said on Sunday. * SUPPLY: Supply concerns eased as Chile's state copper miner Codelco said it had reached an agreement with a union at its Ministro Hales mine in northern Chile, following early talks on a new collective labor contract.