BUZZ-Shares in several Saudi insurers surge on Q2 earnings

** Shares in several Saudi Arabian insurers rise sharply in unusually heavy trade after they report second-quarter earnings ** Saudi United Cooperative Insurance climbs 7.2 percent to 15.70 riyals after it swings to net profit before tax of 30.6 million riyals ($8.16 million) from loss of 40.4 million riyals in corresponding quarter of 2015 ** Al Rajhi Takaful gains 3.8 percent to 23.40 riyals after reporting 55 percent jump in quarterly net profit to 24.4 million riyals ** Alinma Tokio rises 1.