DUBAI, Oct 13 (Reuters) - Positive third-quarter earnings from affiliates of Saudi Basic Industries 2010.SE supported Saudi Arabia's stock index .TASI in early trade on Thursday but the rest of the Gulf was weak, following global shares lower.

Yanbu National Petrochemical 2290.SE (Yansab) climbed 2.0 percent after it reported a third-quarter net profit of 607.6 million riyals ($162.1 million), more than double the year-earlier figure. The result was broadly in line with the 624.7 million riyal average forecast of analysts.

Saudi Kayan Petrochemical 2350.SE jumped 4.1 percent after it swung to a net profit of 156.32 million riyals from a year-earlier loss of 13.81 million riyals; SICO Bahrain had forecast a profit of 105.00 million riyals and NCB Capital, a profit of 95.00 million riyals. Analysts attributed Kayan's results to higher-than-expected sales and gross margins.

Shares in SABIC were up 1.8 percent and the general Saudi market index was up 0.4 percent after an hour of trade.

Many banks were strong as they reported quarterly earnings. Arab National Bank 1080.SE rose 0.7 percent despite posting a 5.6 percent slide in net profit that was broadly in line with analysts' forecasts.

Bank Aljazira 1020.SE rose 2.0 percent after it reported a 3 percent decline in quarterly net income, and Bank Albilad 1140.SE added 1.2 percent after posting a 12 percent rise in profit.

But Saudi British Bank 1060.SE fell 0.9 percent after saying third-quarter profit fell 12.7 percent to 995 million riyals; analysts had predicted 1.14 billion riyals. It cited a rise in impairment charges for credit losses as the Saudi economy weakened because of low oil prices.

Dubai's index .DFMGI continued to slide, edging down 0.4 percent after Asian shares pulled back on weak Chinese economic data and U.S. Federal Reserve minutes indicating a likely rate increase in December. MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS was down 1.4 percent.

Emaar Properties EMAR.DU , Dubai's top real estate firm, was down 0.9 percent.

Qatar's main index .QSI slipped 0.3 percent with three-quarters of traded shares declinig. Petrochemical producer Industries Qatar IQCD.QA lost 0.8 percent.

(Reporting by Celine Aswad; Editing by Andrew Torchia and Alison Williams) ((celine.aswad@thomsonreuters.com)(+9715 62247653)(Reuters Messaging: celine.aswad.thomsonreuters.com@reuters.net))