LME copper weighed by increasing speculative short-selling, slowdown in U.S. demand; pick-up in Chinese demand helping to offset price decline, but stronger recovery unlikely until 2H07, says Citigroup's Alan Heap. Notes rising Chinese copper imports, better performance of SHFE copper futures against LME copper futures indicates Chinese demand improving. Lowers forecasts for 1H average copper price to $5,952/ton, 2H average price at $6,834; LME 3-month copper last at $5,450/ton, +$35 on London PM kerb. Adds, recovery in U.S. copper demand late 2007, along with Chinese restocking, to provide significant support to copper price at that time.