U.S. oil claws back some ground, but oversupply worries persist

SEOUL (Reuters) - U.S. oil prices rose on Friday to claw back some of the ground they lost in the previous session, but growth in U.S. crude stockpiles and ongoing concerns about the global economy kept markets under pressure.U.S. West Texas Intermediate (WTI) crude futures , were up $1.37, or 3.07 percent, at $45.98 per barrel at 0042 GMT, having earlier rising as high as $46.05 per barrel. They ended Thursday down 3.48 percent, or $1.61, at $44.61 a barrel.Brent crude had yet to trade. It..