The project, which is estimated to be as big as the first phase, involves the expansion of the existing ethane cracker and aromatics complex, and the construction of at least 15 downstream chemical production plants. The central element will be the construction of additional furnace capacity for the existing ethane cracker at the complex, which will be supplied with an extra 30 million cubic feet a day of ethane feedstock. Capacities for the naphtha reforming unit and aromatics plants will also be increased to handle an additional 2.5 million-3 million tonnes a year (t/y) of naphtha and 2 million t/y of reformate. Also, a new metathesis unit will be built, fed with a butane/propane stream and ethylene to produce propylene. A total of 17 new chemical derivative production facilities will be built (see box). The scope of works also covers a considerable offsites and utilities element, the installation of feedstock pipelines, storage facilities, a new jetty and a materials handling facility. International consultants have been invited to submit prequalification applications by 30 October for the joint front-end engineering and design and project management consultancy covering the expansion. The prospective bidders are Foster Wheeler and KBR of the US, Australia's WorleyParsons, Paris-based Technip and Japan's JGC Corporation. A tender is likely to be issued in November, with an award due in the first quarter of 2008. A final investment decision on whether to proceed with the mega-project is only likely to be made once most of the engineering is done and the joint venture partners have a better idea of the overall cost of the project. Petro-Rabigh's first phase, which is under construction, involves the expansion of the existing 400,000-barrel-a-day (b/d) refinery at Rabigh by 80,000 b/d and the development of a 1.3 t/y ethane cracker and a series of downstream petrochemicals process units (MEED 5:8:05). It also includes a plastics conversion park, which is a key component of Riyadh's strategy to create a more labour-intensive and substantial downstream manufacturing base. Petro-Rabigh is planning to raise $2,250 million through an initial public offering of shares on the Riyadh stock market. It applied to the Capital Market Authority to launch the offering in July. If it goes ahead, it will be the largest ever share sale by a petrochemicals firm in the kingdom (MEED 21:9:07).