MIDEAST STOCKS-Abu Dhabi hit after bank merger talk quashed; Saudi slips but Egypt resilient

* Abu Dhabi's UNB, ADCB, ADIB drop after denying merger rumours * Dubai's Shuaa gains as investors see upside with new acquirer * Saudi pulls back on profit taking, banks weak * Egypt resilient as foreign buyers continue to accumulate shares By Celine Aswad DUBAI, Nov 20 (Reuters) - Shares of three of Abu Dhabi's top lenders pulled back on Sunday after the banks denied they were in merger talks, while Saudi shares were hit by profit taking. Egypt's stock market gained as foreign funds continued