DUBAI, Oct 20 (Reuters) - Saudi Arabia's stock market rose in early trade on Thursday as the banking sector rallied following the kingdom's mammoth international bond sale, which could help to unclog liquidity bottlenecks in the economy. Other Gulf bourses were mixed.

Riyadh's stock index .TASI added 1.2 percent as all but three listed Saudi banks advanced, with Samba Financial Group 1090.SE , which earlier this week had reported a drop in third-quarter net income, adding 4.0 percent.

The kingdom conducted the largest emerging market bond sale on Wednesday, selling $17.5 billion of debt in the government's first international offer while attracting investor orders totalling almost four times that amount.

Other stock market sectors, however, were driven mainly by quarterly corporate earnings.

Saudi Electricity Co 5110.SE soared 8.0 percent after its third-quarter net profit jumped 50.8 percent to 4.40 billion riyals ($1.17 billion). Analysts at NCB Capital had forecast 1.90 billion riyals.

Saudi Telecom Co 7010.SE rose 3.3 percent after reporting profit of 2.15 billion riyals, down 7.5 percent year-on-year but in line with forecasts.

But rival Etihad Etisalat 7020.SE (Mobily) slumped 8.8 percent after reporting a net loss of 167.7 million riyals versus a loss of 158.3 million riyals in the year-earlier period. Analysts had forecast a profit of 15.06 million riyals.

Retailer Fawaz Alhokair 4240.SE dropped 5.2 percent on an 81.1 percent slump in quarterly earnings to 58.7 million riyals. EFG Hermes had forecast quarterly profit of 244.13 million riyals, while NCB Capital had estimated 269 million riyals. The company cited decrease in sales, lower gross margins and higher finance expenses.

Saudi International Petrochemical 2310.SE (Sipchem) fell 4.4 percent after it swung to a net loss of 59 million riyals from a profit of 71.6 million riyals; analysts had forecast a 30.6 million riyal profit.

Rabigh Refining and Petrochemical 2380.SE was down 5.4 percent after reporting a narrower net loss of 217 million riyals compared with a year-ago loss of 460 million riyals.

Elsewhere, Dubai's index .DFMGI edged up 0.5 percent with DXB Entertainments DXBE.DU rising 3.9 percent in active trade. But neighbouring Abu Dhabi's index .ADI pulled back 0.5 percent with blue-chip lender First Gulf Bank FGB.AD falling 1.8 percent as investors booked profits on recent gains.

In Doha, the main index of the 20 most valuable shares .QSI fell a further 0.2 percent. Commercial Bank COMB.QA , which reported a net loss earlier this week, slipped a further 1.3 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))