Oil prices slide on profit-taking after two-day jump

By Keith Wallis SINGAPORE (Reuters) - Oil prices dropped on Friday as investors took profits following a seven-percent rise in the last two sessions, amid doubts that OPEC's first planned output cut in eight years would make a substantial dent in the global crude glut. Brent crude futures had fallen 63 cents to $48.61 a barrel by 0645 GMT, after settling the previous session up 55 cents, or 1.1 percent. U.S. crude , was down 58 cents at $47.25, after closing up 78 cents and having touched a one-