Natural-gas futures close up over 4%; oil tops $87

    By Myra P. Saefong and Carla Mozee     Natural-gas futures finished with a gain of more than 4% on Thursday, as a smaller-than-expected increase in weekly U.S. supplies lifted prices to a 21-month high, while oil prices rebounded after recent declines to top $87 a barrel.     Natural gas for May delivery NGK13 -0.14%...