BUZZ-Zain Saudi tumbles on Q2 earnings miss

** Shares in Saudi Arabian telecommunications operator Zain Saudi fall 5.7 percent to 7.50 riyals ** Company reported net loss of 329 million riyals ($87.8 million) in three months to June 30 versus loss of 201 million riyals in prior-year period ** Analysts polled by Reuters had on average forecast quarterly loss of 222.1 million riyals ** Stock testing technical support on May low of 7.40 riyals; next support is February low of 5.45 riyals ** Saudi Arabia's stock index slips 0.4 percent (Repor