Saudi Aramco and US Dow Chemical Company is to immediately start building a $20-billion integrated chemicals complex in Jubail, Saudi Arabia, Aramco said on Monday.

The joint venture called 'Sadara Chemical Company' will build one of the world's largest chemical facilities, the state-run Saudi energy giant said, producing over 3 million metric tonnes of chemical products and plastics a year.

'This enterprise will play a key role in the Kingdom's industrial and economic diversification while contributing to the creation of thousands of high quality jobs,' Khalid Al-Falih, president and CEO of Saudi Aramco, said in a statement.

Construction is to start immediately, with the first production units expected on line in the second half of 2015 and all units expected to be up and running in 2016.

Sadara is expected to generate sales of around $10 billion within a few years of operation and generate thousands of jobs, Aramco said.

Sources told Reuters last week the project, first announced in 2007, would be finalised by the end of July or early August.

The joint venture will give Dow access to cheap Saudi gas feedstock and a production facility close to the customers in the booming Asian market, Africa and Europe.

For its part, Saudi Aramco gets a dedicated revenue source for the foreseeable future, part of its plan to expand its petrochemical industry and diversify away from oil alone.

The complex will be able to crack a wide range of feedstocks and produce polyurethans, propylene oxide, propylene glycol, elastomers, polyethylene, glycol ethers and amines, the company said.

Bidding for the construction of several parts of the project has already started. – Reuters