State-run oil giant Saudi Aramco expects to finalise by the end of 2017 on plans for a joint oil-to-chemicals project with Saudi Basic Industries Corp (Sabic), Aramco's chief executive Amin Nasser was quoted as saying by Reuters.

The project, known as COTC, is a key to plans for a chemicals complex costing $20 billion or more, and will be the first major scheme involving the two state giants, the report said.

Nasser said that they have completed the feasibility, and are at a stage where the companies need to work together and make some decision about proceeding with the project, Reuters said.