US STOCKS-Wall St to open lower as China concerns mount
* EPL Oil to be acquired by Energy XXI for $2.3 bln
* Express slumps after outlook
* Copper drops to lowest level in nearly four years
* Futures down: Dow 46 pts, S&P 6.25 pts, Nasdaq 13.25 pts
By Chuck Mikolajczak
NEW YORK, March 12 (Reuters) - U.S. stocks were poised to fall at the open, putting the S&P 500 on track for a third straight decline, as concerns grew over the strength of China's economy.
* London copper, seen as a proxy for China's economic health, fell for a fourth day to its lowest level since July 2010. Recent China data has suggested signs of economic slowing, while the country's first-ever bond default last week has increased concerns financing deals that use the industrial metal as collateral could unravel.
* Geopolitical issues also continue to be monitored by investors as earnings season has drawn to a close and amid a light economic calendar this week, leaving investors without a catalyst to push the benchmark S&P index higher after its most recent record close on March 7.
* Ukraine's government appealed for Western help on Tuesday to stop Moscow annexing Crimea but the Black Sea peninsula, overrun by Russian troops, seemed fixed on a course that could formalize rule from Moscow within days. Continuación...