BUZZ-Riyad Bank shares sag after Q4 earnings tumble

Jan 16 (Reuters) - ** Shares in Riyad Bank, Saudi Arabia's fourth-largest lender by assets, drop 2.3 percent to 10.85 riyals ** Bank posted 65.6 percent fall in fourth-quarter net profit to 293 million riyals ($78 million); analysts polled by Reuters had on average forecast 780 million riyals ** It cited 47. ...