Aug 10 (Reuters) - Copper prices fell on Monday, with Shanghai copper hitting its lowest in more than a month, as traders were wary of a fresh flare up in Sino-U.S. tensions and on considerable uncertainty on whether U.S. policymakers could approve fresh stimulus aid.

The most-traded September copper contract on the Shanghai Futures Exchange ended down 2.3% at 50,230 yuan a tonne, having dropped to its lowest since July 8 at 49,580 yuan ($7,115.90) a tonne earlier in the session.

Three-month copper on the London Metal Exchange dipped 0.1% to $6,305 a tonne by 0704 GMT, having lost 1.6% last week, the biggest weekly drop since mid-May.

Investors were circumspect after U.S. President Donald Trump signed two executive orders banning WeChat, owned by Chinese tech giant Tencent, and TikTok in 45 days' time while announcing sanctions on 11 Chinese and Hong Kong officials.

Talks of another U.S. stimulus bill to support the world's biggest economy fell apart on Friday. However, hopes grew on Sunday that a stand-off would end between U.S. Democrats and the White House on a new support package.

"Market is just washing out the weak longs, making those people with longs cover their positions in this sell-down ... but in relative value, copper got sold off so much compared with oil and equities," said a Singapore-based metals trader.

"LME copper will try to test the $6,600s. Copper won't hit $7,000 so fast, especially when it's in surplus. It'll need to wait for a U.S. stimulus bill," the trader said.

FUNDAMENTALS

* China's July new bank loans could fall from June but still likely to be higher on-year.

* ShFE launched aluminium and zinc options on Monday and Trafigura and Chalco were among the first participants, the exchange said.

* China's Henan Shenhuo Group switched on the third 150,000-tonne production line of its Yunnan aluminium smelting project.

* Canada will slap retaliatory tariffs on C$3.6 billion ($2.69 billion) worth of U.S. aluminum products.

* LME aluminium fell 0.3% to $1,766 a tonne, while zinc declined 0.9% to $2,382 a tonne. In Shanghai, nickel dropped 1.7% to 113,180 yuan a tonne and lead decreased 1.6% to 16,195 yuan a tonne.

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($1 = 6.9675 yuan) (Reporting by Mai Nguyen, Editing by Sherry Jacob-Phillips)