(Adds comments on GCC cooperation, context)

DUBAI, Nov 28 (Reuters) - State-owned Abu Dhabi National Oil Co (ADNOC) ADNOC.UL plans to almost triple its petrochemical production to an annual 11.4 million tonnes by 2025 from 4.5 million tonnes at present, group chief executive Sultan Al Jaber said on Monday.

"To achieve this we will seamlessly integrate our petrochemical and refining business, and as supplies of gas become tighter, we will expand our feedstock beyond ethane to include naphtha," Jaber said in a speech at an energy industry conference.

Jaber did not give any details of ADNOC's expansion plan but said the company aimed to take advantage of a shift in demand from lower-growth markets in the West to high-growth markets in Asia.

He also suggested that petrochemical producers in the six-nation Gulf Cooperation Council should explore new ways of working together, including joint investments in projects.

"By working together, leveraging our combined strengths, aligning our interests and investing together, we can extend our reach, increase our competitive advantages and grow our market share."

ADNOC's petrochemicals are produced by Abu Dhabi Polymers Co (Borouge), which makes polyolefin, and Ruwais Fertilizer Industries (Fertil), which produces urea and ammonia fertilisers.

(Reporting by Maha El Dahan; Writing by Andrew Torchia) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))