By Celine Aswad

DUBAI, May 3 (Reuters) - Saudi Arabian stocks fell on Wednesday after oil prices slipped, while an interview by the top economic policy official, Deputy Crown Prince Mohammed bin Salman, did little to boost sentiment. Other regional bourses were mixed in quiet trade.

Advanced Petrochemical 2330.SE dropped 2.5 percent after the polypropylene maker posted first-quarter net income of 124 million riyals ($33.1 million), down 12.9 percent from a year ago and below NCB Capital's prediction of 149 million riyals.

Other petrochemical makers were also weak after Brent crude slipped below $51 a barrel overnight to its lowest close this year. Riyadh's stock index .TASI lost 0.6 percent in modest trading volume.

The prince said the government would focus on investing in the mining sector, developing the weapons industry, supporting growth of an auto industry and improving the kingdom's logistics, both sea and air.

He also said authorities would announce a programme to address Saudi Arabia's shortage of private housing in the third quarter of this year. But he did not give a time frame or expected expenditure on those projects.

Among companies that could benefit from the government's industrial investment, Emaar the Economic City 4220.SE edged up 0.3 percent, extending the previous session's 4.6 percent gain, but Saudi Automotive Services 4050.SE gave back most of Tuesday's rise and fell 2.9 percent.

Saudi Mining Co 1211.SE (Ma'aden) the only listed company directly involved in mining, edged up 0.5 percent. National Metal Manufacturing and Casting 2220.SE rose 0.7 percent.

Small ground freight and logistics company Batic Investments and Logistics 4110.SE added 1.4 percent in active trade.

Elsewhere, Dubai's index .DFMGI edged down 0.5 percent as Bahraini investment firm GFH Financial GFH.DU slumped 8.9 percent. The company reported quarterly net income attributable to shareholders of $31.91 million, up from $6.06 million a year earlier, but the stock had already risen sharply over the past week in anticipation of strong earnings.

Twenty-two other shares declined in Dubai, including builder Arabtec ARTC.DU , which fell 2.4 percent.

In Abu Dhabi, the index .ADI rose 0.6 percent as the largest listed lender, First Abu Dhabi Bank NBAD.AD , climbed 1.4 percent.



QATAR'S OOREDOO

Qatar's index .QSI lost 0.4 percent to a five-month low as telecommunications operator Ooredoo ORDS.QA dropped 2.3 percent. Its Omani unit looks set to face fresh competition after Abu Dhabi's Etisalat ETEL.AD joined Saudi Telecom 7010.SE and Kuwait's Zain Group ZAIN.KW in bidding for Oman's third mobile licence.

Kunal Damle, senior institutional sales broker at SICO Bahrain, said all the bidders had a strong cash position and would not need to raise debt to operate in Oman. He believes Saudi Telecom and Zain stand the best chances of winning.

"From a consumer's standpoint, Oman would be better off with the product offering from STC's VIVA brand. However, the decision may hinge on the fact that Kuwait is a big investor in the sultanate," Damle added.

At present, Oman Telecommunication OTL.OM and Ooredoo Oman ORDS.OM both have equal market shares of around 41 percent. Omantel was flat on Wednesday while Ooredoo Oman lost 0.4 percent.

The Egyptian index .EGX30 added 0.6 percent in thin trade with declining stocks in the broad market outnumbering gainers by 93 to 71.



WEDNESDAY'S HIGHLIGHTS



SAUDI ARABIA



* The index .TASI fell 0.6 percent to 6,968 points.



DUBAI



* The index .DFMGI lost 0.5 percent to 3,419 points.



ABU DHABI



* The index .ADI added 0.6 percent to 4,581 points.



QATAR



* The index .QSI fell 0.4 percent to 9,955 points.



EGYPT



* The index .EGX30 added 0.6 percent to 12,604 points.



KUWAIT



* The index .KWSE gained 0.6 percent to 6,799 points.



BAHRAIN



* The index .BAX lost 0.6 percent to 1,331 points.

OMAN



* The index .MSI edged down 0.3 percent to 5,492 points. > (Editing by Andrew Torchia) ((celine.aswad@thomsonreuters.com)(+9715 6224 7653)(Reuters Messaging: celine.aswad.thomsonreuters.com@reuters.net))