State-owned Qatar Petroleum and Anglo-Dutch oil giant Shell signed Sunday a heads of agreement to build a petrochemical complex in the energy-rich Gulf state valued at $6.4 billion. Qatari energy minister Mohammed al-Sada and Peter Voser, chief executive officer of Shell signed in Doha the agreement that "sets the scope and commercial principles for the development of a world-scale petrochemicals complex in Ras Laffan Industrial City," a joint statement said. This agreement follows the conclusion of a joint feasibility study conducted by the two sides, it said, pointing out that Qatar Petroleum will hold an 80 percent equity interest in the project and Shell 20 percent. Sada told reporters at the signing ceremony that the value of the contract would be $6.4 billion. The scope under consideration includes a world-scale steam cracker, with feedstock coming from natural gas projects in Qatar, in addition to a mono-ethylene glycol plant of up to 1.5 million tonnes per annum, 300 kilotonnes per annum of linear alpha olefins, and another olefin derivative, the statement said. It said the "cost-competitive petrochemicals products" will be marketed primarily into Asian growth markets. Qatar Petroleum and Shell have delivered Pearl Gas-to-Liquids (GTL) and Qatargas 4 this year, which are two of the world?s largest projects built in Ras Laffan Industrial City, the statement said. The small emirate, which holds the world's third-largest gas reserves, last year celebrated raising its production capacity for liquefied natural gas to 77 million tonnes annually, enforcing its position as the world's largest producer.