Saudi-based Rabigh Refining and Petrochemical Co (PetroRabigh) is looking for firms interested to start work on the second phase of its giant petrochemicals complex, industry sources said on Sunday.

PetroRabigh, a joint venture between state oil giant Saudi Aramco and Sumitomo Chemical inaugurated the first phase of their complex in November. It can produce an annual 18 million tons of refined products and 2.4 million tons of petrochemicals. Long-term growth in petrochemical demand in China has encouraged Aramco and Sumitomo to consider moving forward with the estimated 25 billion Saudi riyals ($6.67 billion) expansion.

PetroRabigh is looking at producing about 17 new products, from the expansion, the company's chief executive, Ziad Labban, told Reuters in November.

"They have just issued the solicitation of interest, there are seven (construction) packages...Contractors are requested to respond by the end of this month," said one source.

Each package consists of several process units, one contractor said. Japan's JGC Corporation is currently conducting a feasibility study on phase II which is due to be completed by the third quarter of this year. A final investment decision on the project will be taken once the study is completed and reviewed.

As part of the expansion, firms will consider increasing the capacity of the existing ethane cracker to take in an additional 30 million cubic feet per day (cfd) of ethane feedstock. The venture will also consider building a new aromatics complex using around 3 million tons per year (tpy) of naphtha as feedstock. It is also look at constructing various petrochemical units. PetroRabigh, located in Rabigh on the west coast of Saudi Arabia, caters mainly to the Saudi market and "high net" areas such as Europe and North Africa. It can process 400,000 barrels of crude per day, accounting for about 19% of Saudi Arabia's total refining capacity.