DUBAI - Saudi Arabia's stock market barely moved early on Thursday after Riyadh reported an attack on two oil tankers by Yemen's Iran-aligned Houthi movement, suggesting investors do not expect the incident to have much of an economic impact.

The main stock index fell 0.3 percent in the first hour of trade and shares in National Shipping Co of Saudi Arabia (Bahri) was 0.2 percent lower after it said one of its vessels suffered minor damage in the attack.

Oil prices rose only modestly after Saudi Arabia said it was suspending crude shipments through one Red Sea shipping lane because of the attack. Brent crude futures added 0.9 percent to $74.59 a barrel on Thursday morning after gaining 0.7 percent on Wednesday, when the attack reportedly occurred.

Credit default swaps, used to insure against the risk of a Saudi sovereign debt default and an indicator of geopolitical tensions in the Gulf, rose marginally on Thursday morning. Other Gulf stock markets mostly traded sideways.

Al Rajhi Bank, Saudi Arabia's second largest bank by assets, was up 0.5 percent after reporting a 17.7 percent rise in second-quarter net profit to 2.57 billion riyals ($685 million), at the high end of analysts' forecasts.

Saudi Arabian Mining Co (Ma'aden), the Gulf's largest miner, was 1.2 percent down despite posting a 45.3 percent jump in second-quarter net profit. The results were short of forecasts by SICO Bahrain and EFG Hermes.

Saudi Arabia's stock index has surged 16 percent this year as foreign investors anticipate the market's planned entry into emerging market benchmarks next year.

Many fund managers now view the Saudi market as richly valued, with Saudi Basic Industries Corp (SABIC) valued at over 20 times trailing earnings.

But major Saudi investment bank Jadwa said in a report on Wednesday that the market could rise further in coming months as active foreign funds began entering the market ahead of Riyadh’s entry into MSCI’s emerging market index.

“We view a rise of at least 20 percent between now and early 2019 as totally plausible,” which would push the stock index to around 10,000 points, Jadwa said.

In Abu Dhabi, where the index slipped 0.2 percent, First Abu Dhabi Bank fell 1.1 percent early on Thursday. On Wednesday the lender reported a 19 percent year-on-year gain in quarterly profit.

Dubai's main index was almost flat as Dubai Islamic Bank climbed 0.4 percent. Qatar's benchmark was also little changed with Qatar Islamic Bank, the main mover, adding 0.5 percent.

(Reporting by Tom Arnold; Editing by Andrew Torchia) ((Tom.arnold@thomsonreuters.com))