UPDATE 7: Emaar stocks drop as Dubai index falls, Abu Dhabi also down.
Saudi Basic Industries Corp (SABIC) hit a 14-month closing high after oil prices reached their highest level since late October, helping Saudi Arabia's index rise for a third straight session.
Saudi Basic Industries Corp (SABIC) climbed 3.3 percent and Rabigh Refining and Petrochemical Co added 0.8 percent.
Rising crude prices gave Saudi petrochemical producers an advantage over rival manufacturers from higher tax countries. Oil is up 2 percent at $80.16 a barrel at 4.18pm Dubai time, having touched $81.16 intraday, its highest level since Oct. 26.
Samba Financial Group climbed 1 percent and al-Rajhi Bank added 1.1 percent.
The index rose 0.8 percent to 6,202 points, although volumes were below 100 million shares for the fifth session running. The moving three-month daily average is 147 million.
Dubai bluechips gave up gains as investors book profits from the early-session two-week high.
Emaar Properties fells 2.4 percent, with traders little moved by the firm saying it will make a 10 percent return on Burj Dubai, the world's tallest tower that will open late Monday. The developer also ruled out a merger with troubled rival Nakheel.
The previous day's biggest gainers suffered the brunt of Monday's sell-off, with Dubai Financial Market and Arabtec each dropping 2.5 percent.
"The market had been going up for a few days before the year-end so it's natural to see some profit taking," said Haissam Arabi, chief executive and fund manager at Gulfmena Alternative Investments.
"The market is taking a breather, but we could still be looking at a short-term rally."
The index fell 1.9 percent to 1,830 points.
"My expectation is for the UAE markets to be the best performers regionally by the end of the year, but this will take some time and I don't think will happen in the first half of the year," added Arabi.
"There are some pit stops along the way such as the earnings outlook for the first quarter and whether we will start seeing the real economy pick up and some top-line growth."
Banks, telecoms and property stocks all slid on thin volumes as Abu Dhabi's index tracked regional losses.
Emirates Telecommunications Corp (Etisalat) fell 0.9 percent, Abu Dhabi Commercial Bank slipped 0.6 percent and Abu Dhabi Islamic Bank dropped 1 percent.
First Gulf Bank bucked the downward trend, rising 0.9 percent after the lender said it had received permission to extend a share buy-back programme.
The index fell 0.5 percent to 2,758 points, its second decline in three sessions. Volumes fell below 40 million shares for the third session in four.
Kuwait's benchmark suffered its largest single-session decline for five weeks on the first day's trading of 2010, as investors cashed in end-of-year gains.
Bluechips tumbled, with Agility plunging 8.8 percent to a 50-week closing low, while Zain dropped 5.9 percent. The latter has now fallen 30 percent since September 8, the day major shareholder the Kharafi group said it had agreed a deal to sell a 46 percent stake in the telecoms operator.
"We were told the takeover would take four months, so most expectations are that the deal will now not take place, but we will have to wait and see," said Naser al-Nafisi, general manager for Al Joman Center for Economic Consultancy in Kuwait.
The benchmark dropped 1.6 percent to 6,891 points.
Qatar's index also stumbled, falling 0.7 percent to 6,959 points in its fourth decline in five sessions and lowest close for almost four weeks. Volumes were the second-lowest of the past 16 weeks.
Barwa Real Estate dropped 1.2 percent and Doha Bank fell 1.3 percent.
Bahrain's measure fell 0.8 percent to 1,447 points.
Oman's index made its largest one-day decline for almost two weeks as investors cashed in from the previous day's 10-week closing high.
"The market should be positive in January and going into February as investors buy stocks ahead of dividend payouts," says Sayed Quadry, vice-president of business development at Amwal Investment in Muscat.
"It's just some profit-taking today and any dips should be seen as a buying opportunity. It's pretty much local retail investors that are active, with maybe a few regional buyers coming in."
Bank Muscat was the biggest drag, dropping 2.7 percent, while other bluechips also struggled. Oman Telecommunications Co (Omantel) and Bank Dhofar lost 0.5 and 1.2 percent respectively.
The benchmark fell 0.8 percent to 6,420 points.