* Egypt investors think IMF loan deal more probable
* Fears ease that Saudi is cutting financial aid to Cairo
* SABIC units diverge in Saudi after Q3 earnings
* Saudi banks mixed as results vary
* UAE, Qatar follow global shares lower
By Celine Aswad
DUBAI, Oct 13 (Reuters) - Egypt's stock market surged on Thursday as local investors welcomed news that Saudi Arabia had deposited $2 billion in the Egyptian central bank. Gulf markets were mixed.
Cairo's index of the 30 most valuable companies rallied 3.9 percent to 8,505 points in its heaviest trade since early August.
Global Telecom soared 11.6 percent to 5.20 Egyptian pounds. Investment bank EFG Hermes jumped 4.4 percent.
Egyptian state news agency MENA reported the Saudi deposit on Wednesday night, saying it would boost the central bank's foreign currency reserves.
The prime minister told Reuters on Thursday that the deposit had already been received in September and included in that month's foreign reserves total, which stood at $19.6 billion.
Nevertheless, investors welcomed the news because it appeared to bring Egypt closer to clinching a $12 billion International Monetary Fund loan, which depends on Cairo obtaining other support.
The deposit also eased fears that Saudi Arabia might be withdrawing its financial support of Egypt. Those fears were fanned earlier this week when a government official said Saudi Aramco had told the Egyptian state oil company that it was halting the supply of refined oil products to the country.
That caused the Egyptian pound to tumble more than 10 percent against the U.S. dollar in the black market to record lows.
Saudi Arabia's index lost steam in the final hour of trade and closed 0.02 percent up at 5,694 points, 60 points off the day's high. The index was up 1.1 percent for the week on firmer crude oil prices and third-quarter corporate earnings that were generally in line with analysts' expectations.
Yanbu National Petrochemical (Yansab), a unit of Saudi Basic Industries, dropped 2.3 percent on Thursday, after trading as much as 3.3 percent higher earlier in the day.
It reported third-quarter net profit of 607.6 million riyals ($162.1 million), more than double the year-earlier figure. The result was broadly in line with the 624.7 million riyal average forecast of analysts.
But Saudi Kayan Petrochemical, another SABIC affiliate, closed up 4.1 percent after it swung to a net profit of 156.32 million riyals from a year-earlier loss of 13.81 million riyals; SICO Bahrain had forecast a profit of 105.00 million riyals and NCB Capital, a profit of 95.00 million riyals. Analysts attributed Kayan's results to higher-than-expected sales and gross margins.
Shares in SABIC rose 0.6 percent.
Some banks gained after they reported earnings. Arab National Bank rose 1.6 percent despite a 5.6 percent slide in net profit that was broadly in line with analysts' forecasts. Bank Aljazira climbed 3.0 percent after it reported a 3 percent decline in net income.
But Saudi British Bank fell 0.9 percent after saying third-quarter profit fell 12.7 percent to 995 million riyals; analysts had predicted 1.14 billion riyals. It cited a rise in impairment charges for credit losses as the Saudi economy weakened because of low oil prices.
Dubai's index continued to slide, dropping 0.6 percent after Asian shares pulled back on weak Chinese economic data and U.S. Federal Reserve minutes suggested interest rates were likely to rise in December. MSCI's broadest index of Asia-Pacific shares outside Japan was down 1.2 percent.
Emaar Properties, Dubai's top real estate firm, fell 1.3 percent.
Qatar's main index slipped 0.1 percent with a little over half of traded shares declining. Qatar National Bank , which reported a rise in net profit for the last quarter earlier this week, pulled back 0.3 percent.
* The index edged up 0.02 percent to 5,694 points.
* The index lost 0.6 percent to 3,335 points.
* The index fell 0.4 percent to 4,347 points.
* The index jumped 3.9 percent to 8,505 points.
* The index edged down 0.1 percent to 10,390 points.
* The index pulled back 0.4 percent to 5,328 points.
* The index fell 0.4 percent to 5,660 points.
* The index rose 1.3 percent to 1,145 points.
Editing by Andrew Torchia, Larry King