Oil edged further above $37 a barrel on Thursday but remained within sight of an 11-year low reached this week, as signs of a tighter U.S. market raised hopes a supply glut will ease. U.S. crude has gained support from falling inventories, reduced drilling and the lifting of a ban on most U.S. crude exports, which has pushed U.S. crude to a premium to global benchmark Brent for the first time in about a year. U.S. crude (CLc1) was up 20 cents at $37.70 after gaining more than 8 percent this week.