Oil prices wavered Tuesday, caught up in uncertainties about global crude demand, while natural gas continued to decline in Europe. By 10:30 GMT (12:30 in Paris), a barrel of Brent North Sea crude for December delivery was down 0.20 percent to $91.44. U.S. West Texas Intermediate (WTI) for November delivery was down 0.25 percent at $85.25 a barrel.