BEIJING, April 20 (Reuters) - London aluminium and nickel
prices fell for a second day on Friday as a rally driven by
fears of supply disruptions caused by U.S. sanctions on Russia's
United Company Rusal, the world's second-biggest
aluminium producer, lost momentum.
    Prices have started to retreat amid no signs of further
sanctions yet, brokerage Sucden said in a note, adding that
conditions remain "nervous and choppy amid the overhanging
uncertainty." Short-term direction was "likely to be
headline-driven," it added.  
    Aluminium is on track for a weekly rise of 6.3 percent in
London and is up 21 percent so far this month. It climbed 11.9
percent last week in the wake of the Rusal sanctions announced
on April 6, its biggest weekly jump since 1988.
            
    FUNDAMENTALS
    * LME ALUMINIUM: Three-month aluminium on the London Metal
Exchange was down 2.1 percent at $2,432.50 a tonne by
0439 GMT, after ending down 2.1 percent in the previous session.
Earlier on Thursday, it rose to $2,718, the most since May 5,
2011.
    * SHFE ALUMINIUM: The most-traded June aluminium contract on
the Shanghai Futures Exchange was also down 2.1 percent
by the mid-session interval at 14,965 yuan ($2,380.88) a tonne.
    * NICKEL: LME nickel was down 3.4 percent, extending
its 1.3 percent fall on Thursday, when it rose to as much as
$16,690, the most since Dec. 12, 2014, on fears the sanctions
could be broadened to Russian nickel producer Nornickel
.
    * SHFE NICKEL: The most-traded July nickel contract
on the ShFE was down 3.3 percent to 104,180 yuan a tonne, after
rising to its highest since June 2015 on Thursday. The exchange
hiked transaction fees for the July contract from Friday.

    * ALUMINIUM: Rusal is stockpiling large quantities of
aluminium at one of its plants in Siberia because U.S. sanctions
imposed this month have prevented it from selling the metal to
customers, five sources close to the company said.
    * BANKS: Lenders to Rusal are exploring how to get rid of
their exposure before a May deadline set by the United States,
as the fallout from fresh sanctions pulls Russian loan pricing
lower in Europe's secondary market.