Saudi Arabia's stock market fell on Tuesday for the fourth straight day, weakened by a combination of lower oil prices and geopolitical tension in the Middle East, while Egypt's blue-chip index was buoyed by its largest lender.

The Saudi index was down 0.8 percent. The country's second-largest lender by assets Al Rajhi Bank lost 1.1 percent and National Commercial Bank shed 2.3 percent.

Alawwal Bank eased 1.8 percent after reporting a fall in its first-quarter net profit due to higher costs.

Oil prices fell as renewed doubts over U.S.-China trade talks stoked concerns over global growth, while the United States said on Sunday it was deploying the Abraham Lincoln carrier strike group and a bomber task force to the Middle East in response to troubling "indications and warnings" from Iran.

"A combination of lower oil prices, regional instability, U.S. sending carriers to the Gulf will have a negative effect on the regional markets and in particularly Saudi as it is the most looked at market currently," Rami Jamal, portfolio manager at Amwal in Doha said.

Egypt's blue-chip index rose 1.3 percent, with its largest lender Commercial International Bank Egypt adding 2.8 percent. The firm posted an increase in first-quarter net profit, aided by strong net interest margins and deposits.

Eastern Co rose 1.4 percent after saying it would launch a new Black Massal product and expected Black Massal sales to rise by 50 percent from current levels.

Kuwait's blue chip index added 1.9 percent with Zain Kuwait and National Bank of Kuwait gaining 2.7 percent and 4.2 percent, respectively.

Last week, Zain Kuwait reported a 15 percent rise in first-quarter net profit helped by strong growth in Bahrain and Iraq.

The index is on MSCI's watch list for a potential upgrade to emerging market status by mid-June. Kuwait's weight in the emerging market index could reach about 0.51 percent which will result in $2.5 billion of passive inflows, Jaap Meijer, head of equity research at Arqaam Capital said.

The country has seen strong foreign interest over the past year on the back of its FTSE emerging market inclusion last year and the potential upcoming MSCI re-classification, Meijer added.

The Abu Dhabi index slipped 0.4 percent, with Abu Dhabi Commerical Bank shedding 3.7 percent after reporting first-quarter results.

The bank, which formalised a merger with two other lenders last week, reported a 5 percent fall in first-quarter profit, hurt by lower interest income. 

Gulf Cement dropped 6.1 percent, while First Abu Dhabi Bank, the largest in the United Arab Emirates, dipped 0.3 percent.

In Dubai, the index traded 0.3 percent lower, with Islamic Arab Insurance down 7.3 percent and the top loser after denying talks of a merger.

Property firm Emaar Development  fell 1.9 percent. The company reported a 8.3 percent drop in its first-quarter net profit.

The Qatar index was down 0.4 percent, with Mesaieed Petrochemical Holding dropping 2.8 percent.

Qatar National Bank and Qatar International Islamic Bank slipped 1.3 percent and 1 percent, respectively.

(Reporting by Karina Dsouza in Bengaluru; Editing by Kirsten Donovan) ((; within U.S. +1 646 223 8780, outside U.S. +91 80 6749 6373; Reuters Messaging: Reuters Messaging: