DUBAI, United Arab Emirates (AP) — Dow Chemical and the Saudi Arabian Oil Company have agreed to set up a joint venture to build a massive $20 billion chemical complex in the desert kingdom.

The companies said Monday that work on the long-awaited Sadara Chemical Company venture will begin immediately. It should start operations by 2015.

The complex, located in Saudi Arabia’s Jubail Industrial City, will include 26 manufacturing units producing chemical products and plastics for use in the energy, transportation, infrastructure and consumer products industries.

Dow and Saudi Aramco say it will be one of the world’s largest integrated chemical facilities. It will cost $20 billion, including funding from export credit agencies and financial institutions.