By Dylan Bowman and Reuters
Main index closes up for 7th straight session, while Oman, Abu Dhabi continue winning form.
Banking shares led Qatar to its highest close in at least two weeks on Wednesday to make it seven consecutive sessions in a row its benchmark has finished in the black.
Elsewhere Oman and Abu Dhabi also continued their winning form, while Saudi Arabia, Dubai and Bahrain all dropped again.
Kuwait ended lower for the first time in six trading days.
Qatar Islamic Bank, Qatar Commercial Bank and Doha Bank paced the gains on the Doha bourse.
The three lenders finished up 5.18 percent, 1.41 percent and 2.09 percent respectively, helping the main index up 0.91 percent to 12,627.32 points.
"I think what is happening is a movement before the financial statements," said Samer Al-Jouani of Financial Brokerage Co.
"We may see some profit-taking on shares that have really rallied over the last two weeks."
Qatar's bourse, the Gulf's second-biggest gainer, is up more than 30 percent so far this year.
In Muscat, Oman Telecommunications Co. (Omantel) and Raysut Cement Co. drove Oman's main measure to end higher for a second trading day.
Omantel gained 2.82 percent and Raysut climbed 1.68 percent. The benchmark, the Arab Gulf region's best performing index this year, closed 0.9 percent higher at 12,109.10 points.
"There has been excellent local and regional institutional buying today," said Adel Nasr at Muscat-based United Securities.
Banking stocks also steered Abu Dhabi's main measure to a higher close for the second time this week.
Union National Bank closed 3.69 percent higher and National Bank of Abu Dhabi (NBAD) ended 1.42 percent up. National Bank of Umm Al-Quwain was the day's biggest gainer, surging 9.8 percent.
Abu Dhabi's index rose 0.44 percent to 5,148.49 points.
"There is positive sentiment in the banking sector in Abu Dhabi," said Mohamed Alami at Naeem Shares & Bonds.
Shares of Dubai Investment Co. and Dubai Financial Market Co. weighed on Dubai as the main index closed lower for the second day this week.
Dubai Investment slipped 1.63 percent and Dubai Financial Market dropped 1.58 percent, with the measure inching down 0.06 percent to 5,723.06 point.
Saudi Arabia's main index ended weaker for the third time this week, dragged by Samba Financial Group, which fell 3.8 percent, and Al Rajhi Bank, which slipped 1.88 percent.
The kingdom's index, the worst performing measure in the Gulf Arab region this year, closed 0.8 percent lower at 9,688.45 points.
"The market is down due to some profit taking," said Abdulla Al-Aqil, a trader at Saudi-based Samba Financial Group.
Kuwait's main measure closed lower for the first time in six trading sessions, led by Commercial Bank of Kuwait, which fell 1.33 percent, and National Mobile Telecommunications Co. (Wataniya), which decreased 0.84 percent. The index eased 0.04 percent to 15,348.00 points.
Bahrain's main index closed 0.07 percent lower at 2,879.70 points, led by Gulf Finance House which declined 0.47 percent and Bahrain Telecommunications Co. (Batelco), which slipped 0.97 percent.