GLOBAL MARKETS-Equities extend rally; oil rebounds, helping rouble rise

(Updates prices, quote)* European shares after 3-day rally* Rouble bounces over 3 percent, oil above $60 a barrelBy David GaffenNEW YORK, Dec 19 (Reuters) - Equity markets worldwide extended the week&aposs rally on Friday and oil prices rebounded from recent lows, even though market volumes were beginning to thin as investors started to reduce exposure as the end of year approaches, traders said.W