MIDEAST STOCKS-Saudi tumbles on oil, earnings; other markets also weak

* All major Gulf markets fall after oil posts sharp July drop * Saudi Arabia, seen by funds as over-valued, leads losses * DAMAC one of few gainers in Dubai ahead of Q2 results, dividends * Industries Qatar also tracks oil prices * Egypt gives up gains under pressure from regional investors By Olzhas Auyezov DUBAI, Aug 2 (Reuters) - Stock markets across the Middle East fell on Sunday after oil prices dropped again and Saudi Arabia, heavily influenced by the petrochemicals sector, led losses, hit