DUBAI, Jan 15 (Reuters) - Stock markets in the Gulf diverged in early trade on Sunday with Saudi Arabia's bourse supported by small and mid-sized shares while profit taking weighed on Dubai and Abu Dhabi.

Saudi Arabia's index .TASI edged up 0.3 percent in the first half hour; Al Jouf Cement 3091.SE was the top gainer, jumping 5.8 percent.

Almarai 2280.SE rose 0.4 percent after the Gulf's largest dairy company reported a 1 percent increase in fourth-quarter net profit to 488.5 million riyals ($130 million), virtually meeting analysts' forecasts as sales rose marginally and the cost of sales fell. urn:newsml:reuters.com:*:nD5N1E900V

Analysts at NCB Capital said that despite the relatively flat earnings and revenue growth, strong margin expansion from lower operating expenditure and improving sales in Almarai's poultry segment were important positives.

The company, one of the few that give a forward guidance, said: "Given the changing economic environment and the increasing competitive conditions, the company will continue to focus on costs control, efficiency gains and cashflow preservation while maintaining its strategic direction of profitable growth."

Bank Aljazira 1020.SE , the first bank to report earnings in the kingdom, lost 0.8 percent after reporting a 4.4 percent drop in fourth-quarter net profit to 152 million riyals. Aljazira attributed the fall to higher impairment charges for credit losses.

Some other banks were knocked lower as a result, with Saudi British Bank 1060.SE dropping 1.4 percent.

Kuwait's stock market .KWSE , which is often thinly traded, was up 1.6 percent with Boubyan Petrochemical BPCC.KW rising 3.9 percent and the largest logistics firm in the Gulf, Agility AGLT.KW , climbing 3 percent.

"Sentiment is very positive in the market but no change in fundamentals ..." said Bader Al Gahnim, head of regional asset management at Kuwait-based Global Investment House. "From an economic perspective the country is well positioned due to prudent fiscal management and a lower fiscal break-even oil price."

Dubai's index .DFMGI pulled back 0.4 percent on profit taking in some of last week's biggest gainers. Islamic Arab Insurance SALAMA.DU fell 0.7 percent and builder Drake & Scull DSI.DU lost 0.6 percent.

Abu Dhabi's index .ADI was also weakened by profit taking and fell 0.4 percent. National Bank of Abu Dhabi NBAD.AD dropped 1.4 percent; shares in the bank, which is set to merge with First Gulf Bank FGB.AD this quarter, have been volatile for the past week. FGB was down 0.8 percent.

(Reporting by Celine Aswad; Editing by Andrew Torchia and Susan Fenton) ((celine.aswad@thomsonreuters.com; +971 4 4536886; Reuters Messaging: celine.aswad.thomsonreuters.com@reuters.net))