* Brent oil at $78 a barrel boosts Saudi petchems
* Nama Chemicals soars after swinging to first-quarter profit
* Savola hit by quarterly loss, Iran concerns
* Dubai's Arabtec jumps on highest quarter profit since 2014
* Commercial International Bank pulls down Egypt after earnings
By Andrew Torchia
RIYADH, May 10 (Reuters) - Saudi Arabian petrochemical shares surged on Thursday as Brent oil hit $78 a barrel, while most of the region's stock markets fell because of geopolitical tensions after Israeli forces traded fire with Iranian forces in Syria.
The Saudi index rose 0.5 percent as the biggest petrochemical producer, Saudi Basic Industries, added one percent.
Nama Chemicals soared 9.6 percent in its heaviest trade since May 2014 after saying it had swung to a 28.2 million riyal ($7.5 million) profit in the first quarter from a year-earlier loss.
But food producer Savola fell 4.2 percent after it swung to a loss in the first quarter, hit by lower sales in the food and retail sectors and a higher share of losses at an associate.
Savola is one of the few listed Gulf companies with major operations in Iran, which could face tougher conditions after U.S. President Donald Trump said this week he would reimpose economic sanctions on Tehran.
In Dubai, the index fell 0.3 percent as blue chip Emar Properties sank one percent to a 27-month closing low of 4.99 dirhams. The stock is down nearly 22 percent year-to-date, dragged down by the extended slump in United Arab Emirates real estate markets.
Construction firm Arabtec, which had hit a nine-year low on Wednesday, jumped 8.8 percent after reporting a first-quarter net profit attributable to shareholders of 63.6 mln dirhams ($17.3 million), up from 17.6 million dirhams a year ago and its highest profit since the third quarter of 2014.
Abu Dhabi's index dropped 1.1 percent as Abu Dhabi National Energy Co slipped 2.3 percent despite posting a 43 percent rise in first-quarter profit, boosted by higher crude oil prices.
In Egypt, the index sank 1.8 percent as Commercial International Bank, the biggest bank, dropped 3.3 percent. It reported a 17 percent rise in first-quarter consolidated net profit after minority interests, but that was slightly lower than its 21 percent profit rise in the fourth quarter and 23 percent in the third quarter.
* The index rose 0.5 percent to 7,914 points.
* The index fell 0.3 percent to 2,882 points.
* The index dropped 1.1 percent to 4,438 points.
* The index slipped 0.9 percent to 8,750 points.
* The index rose 0.2 percent to 4,797 points.
* The index edged down 0.02 percent to 1,271 points.
* The index edged up 0.1 percent to 4,682 points.
* The index sank 1.8 percent to 17,155 points. (Editing by Elaine Hardcastle)